Abstracts of the 2nd International Electronic Conference on Metals ^†

1. Session: Computation, AI, and Machine Learning on Metals

1.1. An Integrated Experimental and Quantum/Atomic Modelling of FeCrV-Based Refractory Medium Entropy Alloy for Nuclear Application

• Arman Hobhaydar ¹, Xiao Wang ¹, Huijun Li ¹, Nam Van Tran ² and Hongtao Zhu ¹

¹ 

School of Mechanical, Materials, Mechatronic and Biomedical Engineering, University of Wollongong in Australia

² 

School of Materials Science and Engineering (MSE), Nanyang Technological University in Singapore

• Introduction

Rising energy demands and environmental challenges necessitate advancements in nuclear reactor materials to endure harsh conditions, including high temperatures, neutron flux, and oxidation. Medium-entropy alloys (MEAs) offer promising properties like enhanced strength, ductility, and radiation resistance. This study focuses on designing FeCrV-based refractory MEAs for nuclear applications using multi-scale modelling and experimental validation, leveraging the potential of DFT and machine learning to optimize performance and simulate large-scale behaviours.

• Methods

First-principle calculations were performed using VASP, employing the PAW method and PBE-GGA for accurate modelling. AIMD simulations with a 0.5 fs timestep generated training data under constant and increasing temperatures. Neural network potentials were trained using DeepPot-SE. Large-scale MD simulations applied periodic boundaries and NPT equilibration at 300–1023 K. MC/MD methods facilitated atom exchanges, governed by Boltzmann probability, to explore temperature-dependent behaviours and structural evolution.

• Results

XRD and TEM microstructure analyses revealed that the RMEA comprises two distinct phases: BCC1, the nominal alloy phase, and BCC2, a vanadium-rich phase. These two phases were also identified in MD/MC simulations conducted using the DNNP, demonstrating the accuracy of the model. The addition of 8% W to FeCr₂V significantly enhances its mechanical properties, achieving an ultimate compression strength of 1700 MPa and a Young’s modulus of 255.28 GPa. According to the DFT results, these improvements are attributed to a balanced interaction between metallic and covalent bonding, producing a highly irradiation-resistant material with an average vacancy formation energy of 2.66 eV. Dislocation analysis conducted via MD revealed that increasing the temperature enhances dislocation mobility, which further improves the ductility of the alloy.

• Conclusions

In conclusion, a cost-effective FeCr₂V-based RMEA with superior mechanical properties, including high strength, ductility, and irradiation resistance, was successfully designed. With properties surpassing HEAs, this alloy demonstrates improved dislocation mobility at elevated temperatures, highlighting its potential for advanced structural applications in extreme environments.

1.2. Effective Modeling of Cold Rolling of Metals

• János György Bátorfi ^1,2, Jurij J. Sidor ¹ and Tibor Borbély ¹

¹ 

Savaria Institute of Technology, Faculty of Informatics, Eötvös Loránd University Hungary, H-9700 Szombathely, Károlyi Gáspár tér 4

² 

Doctoral School of Physics, Faculty of Science, Eötvös Loránd University Hungary, H-1117 Budapest, Pázmány Péter sétány 1/A

In this work, we extended an existing version of the Flow-Line Model (FLM) to the symmetric cold rolling of technically pure aluminum sheets. Through the modifications, the rolling process can be described with improved precision even in special conditions. The FLM aims to approximate the velocity values at each point of the rollgap using the new analytical function. The difficulty of the FLM models is in finding the correct value of the parameters based on the geometrical dimensions and frictional conditions. Besides the theoretical changes to the model, a set of empirical parameters were introduced, and the equations to determine the value of these empirical parameters were built up based on numerical results of Finite Element Model (FEM) simulations for a wide range of geometrical parameters.

The main theoretical challenge is to approximate the rollgap using a proper function. The distribution of the shear strain rates along the sheet’s thickness was approximated by a power function. The newly introduced empirical parameters were determined by using three non-dimensional factors: (i) the ratio of the actual to minimal coefficient of friction, (ii) the relative reduction in the sheet’s thickness, and (iii) a geometrical ratio expressing the ratio of the rollgap’s length to the sheet’s thickness.

The model was tested for the following regimes of the non-dimensional factors: the thickness reduction was changed from 0.01 to 0.38; the ratio of the pressed arc to the radius was varied between 0.0082 and 0.31; and the ratio of the real to minimal coefficient of friction was changed from 1.05 to 2.5.

The model’s precision determined from the three measured distortion lines (generated by Vickers indentations) was compared to their simulated version.

1.3. Optimization of Copper (II) Leaching Process Using Machine Learning Approaches

• Banza Jean Claude and Linda Sibali
• Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa

Using machine learning approaches such as the artificial neural network (ANN) model, the factors influencing the leaching of copper from contaminated soil using sulphuric acid were determined. The feed-forward back-propagation (BP) algorithm was used for the development, training, and prediction of the artificial neural network model. The pH of the solution, acid concentration, soil-to-liquid ratio, and stirring speed were used as input variables, while the amount of copper (II) leached was used as the output. To build and train the model, 21 datasets were taken from the leaching experiments. We looked at neural networks with one to nine hidden layers to find the one with the best agreement and to find the one that could reduce the discrepancy between the predicted and measured values. A proportion of 70% of data were used for training, 15% for testing, and 15% for validation. During the regression analysis of the four inputs, nine hidden layers, and one output design, the R² value for training was 0.997, that for validation was 0.996, and that for testing was 0.997. The algorithm used was Levenberg–Marquardt with membership 11-11-11-11. The corresponding MSE values were 0.121, 0.133, and 0.105. The findings indicate that the artificial neural network holds great promise for predicting the leaching of copper (II). The results showed that the ANN model’s performance improved as the number of hidden layers increased.

1.4. Phase Equilibrium of Ti-Pt-Nb High-Temperature Shape Memory Alloys Studied Using Cluster Expansion Techniques

• Mordecai Mashamaite, Phuti Ngoepe and Hasani Chauke
• Materials Modelling Centre, University of Limpopo, Private Bag X1106, 0727, South Africa

The effect of adding Nb on TiPt high-temperature shape memory alloys (HTSMAs) was investigated using the universal cluster expansion and first-principle approach. In this study, cluster expansion was utilized to predict ground state structures containing three (3) elements: Ti, Pt, and Nb. The cluster expansion method generated 45 new Ti-Pt-Nb structures, and these were ranked as stable and meta-stable structures based on their formation energies. Among the six (6) predicted structures, the Ti₄Nb₂Pt₂ system was selected around 50:50 on Platinum (Pt)-rich sites since it is the most stable structure on the ground state line. The supercell approach in MedeA (VASP) was used to create large supercells of about 64 atoms. In addition, the Ti₄Nb₂Pt₂ system was studied further by determining the structural, thermodynamic and mechanical properties using the first-principle density functional theory. The Ti₄Nb₂Pt₂ system was found to be the most thermodynamically stable structure due to its negative heat of formation (−0.361 eV/atom). The materials have similar properties as tetragonal Nb-doped TiPt. The mechanical properties of these compounds revealed that they are ductile in nature and mechanically stable. Furthermore, the phonon dispersion curves showed the vibrational stability of the Ti₄Nb₂Pt₂ alloy due to the absence of soft modes. This work suggests that introducing Nb stabilizes the TiPt SMAs, making them potential candidates for high-temperature applications.

1.5. Predicting Corrosion Rate in Oil Wells Using First Principles and Machine Learning

• Santiago Zapata Boada ^1,2, Giovanni Juzga Leon ³ and Helen Flores Ortiz ³

¹ 

PDRA, University of Manchester, UK

² 

Pungo Tech, Ecuador

³ 

Corporacion para la Investigacion de la Corrosion, Piedecuesta 681011, Santander, Colombia

Corrosion in oil wells results from the interaction of factors such as chemical composition, temperature, pressure, and fluid flow. Accurately predicting corrosion rates is crucial for operational efficiency and risk mitigation. Traditional models often have limitations in adapting to new operating conditions and capturing complex interactions between variables, while machine learning models can uncover these interactions. This study aims to develop a hybrid model that combines physical and chemical understanding of corrosion with machine learning approaches. Integrating fundamental corrosion principles with machine learning adaptivity, the model seeks to improve accuracy in predicting corrosion rates, thereby reducing operational costs, downtime, and safety risks. The methodology we applied began with the collection of historical data from a representative set of oil wells (more than 30,000 logs), including corrosion rates, well operating parameters, tubing parameters, and fluid compositions. The dataset was carefully cleaned and transformed, addressing missing values and outliers. To integrate first principles, the NORSOK corrosion model, based on fundamental chemical and physical concepts, was applied to calculate theoretical corrosion rates. Subsequently, machine learning models—such as Linear Models, Bootstrap Forest, and Boosted Tree—were trained using metrics like RSquare and Mean Average Error (MAE) to evaluate performance. Among the tested models, a Boosted Tree model (XGBoost) achieved the best performance, achieving an RSquare of 0.163 and an MAE of 1.39, capturing complex parameter relationships. Incorporating the NORSOK-based first principles ensured the model remained robust under varying conditions. Finally, a hybrid approach combining predictions from both physics- and chemistry-based and machine learning models was deployed in the cloud for real-time corrosion rate predictions. This deployment offers significant cost savings—up to a 30% reduction in chemical treatment costs—and enhances operational efficiency by minimizing downtime due to corrosion events.

1.6. Prediction of the Critical Cooling Rate in the Dependence of the Chemical Composition of Super Duplex Steel X03Cr23Ni6Mo4Cu3NbN

• Kseniya Utkina ¹, Evgeniy Korzun ¹, Leonid Levkov ², Ivan Ivanov ³ and Alexey Yanilkin ⁴

¹ 

Leading Researcher, Ph.D. in Technical Sciences, JSC “RPA ‘CNIITMASH’, Russia, 115088, Moscow

² 

Head of the Laboratory of Special Electrometallurgy, Doctor of Technical Science, JSC “RPA ‘CNIITMASH’, Russia, 115088, Moscow

³ 

Deputy General Director, Ph.D. in Physics and Mathematics, JSC “RPA ‘CNIITMASH’, Russia, 115088, Moscow

⁴ 

Head of the Digital Materials Science Department, Ph.D. in Physics and Mathematics, VSUE “VNIIA”, Russia, 127030, Moscow

• Introduction

Super duplex steel 03Cr23Ni6Mo4Cu3NbN (SDS) is a new development of JSC “NPO ‘TSNIITMASH’, which has high corrosion and strength characteristics which are in demand in the oil and gas industries, as well as in chemical industry and nuclear power engineering. The combination of these characteristics is ensured by uniform distribution of austenite and ferrite. Special attention is paid to the technology of ingots and forgings manufacturing, prevention of formation and growth of σ-phase, and other secondary phases which negatively affect the mechanical and operational properties of steel. The influence of chemical composition and technological parameters, including ingot solidification and forgings cooling rates, on structure formation is investigated using computer modeling and experimental studies.

• Methods

-

Modeling of phase transformations of 1000 chemical compositions is carried out using the program complex Thermo-Calc version 2022a (with PRISMA) using databases TCFE11, MOBFE6.

-

Production of 03Cr23Ni6Mo4Cu3NbN steel samples takes place using electroslag remelting (ESR) with the provision of increased crystallization rates. The cooling rates from 2.5 to 42 °C/s are realized when the forgings are quenched.

-

The chemical composition, microstructure, and impact toughness of steel are determined.

• Results

The influence of alloying elements and cooling rate of forgings on the kinetics of σ-phase formation is described on the basis of computer modeling. Parametric models approximating the results of thermodynamic and kinetic calculations are developed. The models allow us to calculate the fraction of σ-phase at given cooling rates to estimate the value of impact toughness of steel.

• Conclusions

On the basis of regression analysis, the influence of nitrogen, molybdenum, nickel, copper and carbon on the value of critical cooling rate has been established.

The equation for calculation of impact toughness depending on the volume fraction of σ-phase has been proposed.

The possibility of preventing the growth of complex nitrides of CrNbN system, negatively affecting the impact toughness, by controlling the conditions of solidification at ESR has been established.

1.7. Soft Computing Model Application for the Modelling and Prediction of Copper (II) Leaching

• Banza Jean Claude and Linda Sibali
• Department of Environmental Science, College of Agriculture and Environmental Sciences, University of South Africa

Optimising the parameters of leaching while assessing the dynamics of the process kinetics requires an investigation of the effects of different variables. A neural network (NN) and a fuzzy inference system (FIS) were used to evaluate and examine the leaching process. The results showed that increasing the acid concentration and stirring speed, while decreasing the solid-to-solution ratio and pH, enhanced copper (II) leaching. The optimum values obtained from the leaching process for pH 3 were found to be a solid-to-liquid ratio of 1 g/100 mL, an agitation speed of 300 rpm, and an acid concentration of 1 M, with a 97% recovery of copper (II). Diffusion throughout the product layer controlled the leaching rate, and the experimental results suggested that a diffusion-controlled model would provide the best fit. The diffusion-controlled mechanism was indicated by an activation energy of 16.01 kJ/mol. To optimise the parameters of the leaching process, the algorithm training for neural networks (NNs) included the Levenberg–Marquardt method with a membership structure of 7-7-7-7, using the backpropagation (BP) technique for learning. The neural network (NN) method was trained using four input variables, representing leaching parameters, fifteen hidden layers, and one output representing copper (II) leaching recovery. R² values of 0.996, 0.997, and 0.997, respectively, show the validation, testing, and training phases of the ideal trained neural network. An R² value of 0.999 for FIS indicates that the study data can be precisely predicted. ANFIS had a Pearson’s chi-squared value of 0.225, surpassing the ANN’s score of 0.658.

1.8. The Performance of Hybrid R/C-Steel Structures Under Successive Earthquakes

• Paraskevi Konstantinos Askouni
• Department of Architecture, University of Patras, Greece

In the conventional building procedure, numerous circumstances may be discovered regarding building types composed of a lower and older reinforced concrete (r/c) component and an upper and newer steel part, referred to as a “hybrid” building. Established principles of seismic design provide comprehensive instructions for the resistant design of structures built using a single material everywhere. The present seismic norms do not give explicit design and detailing requirements for vertical hybrid structures. There needs to be more investigation in existing research, addressing thisscientific gap. The current study attempts to fill this knowledge gap on hybrid construction performance under successive ground motions, which have been reported in research worldwide in terms of seismic structural performance. Three-dimensional representations of hybrid r/c-steel building frames are subjected to successive ground stimulations across the horizontal and vertical directions, implementing a non-linear response of the frame components over time. The bottom r/c part of the hybrid structures is described as relating to a previous construction using an essential approximation here. Furthermore, two limit interconnections of the structural steel component to the concrete one are identified for investigation in non-linear time history analysis. An evaluation of the arithmetic analysis outcomes of the hybrid frames considering the two limit interconnections is performed. The analysis diagrams of the present dynamic investigations of the 3D hybrid frames exposed to successive ground motions provide helpful insights that offer guidelines for a better earthquake-resistant design of the “hybrid” building form, which does not fall within the scope of the present standards despite being frequently used.

2. Session: Metallic Materials Chemistry

2.1. Environmental Applications of S-Doped g-C₃N₄ in Photocatalytic Degradation of Congo Red Dyes Under Solar Light Irradiation

• SUNEEL and Qazi Inamur Rahman
• Research Scholar, Department of Chemistry, Integral University, Kursi Road, Lucknow-226026 Uttar Pradesh, India

Background: Today, researchers are focusing on preparing photoactive semiconductor materials doped with non-metals; such semiconductors may be considered a prospective route to resolving the worldwide water crisis by degrading organic dyes present in wastewater from the textile industry.

Methodology, results, and conclusions: Herein, we report a facile route to synthesise S-doped graphitic carbon nitride (S-GCN) from thiourea via thermal polymerisation methods. The crystalline nature of the synthesised photocatalyst was examined by utilising X-ray diffraction (XRD), with the peak positions at Bragg angles (2θ) of 13.07° and 27.42°, which correspond to Miller indices of (100) and (002), respectively; however, their functional group purity was evaluated through Fourier transform spectroscopy (FT-IR), and the presence of three distinct bands appearing at 3153 and 1636-1240 indicates the presence of N-H and O-H stretching modes of heterocyclic S-doped g-C-N, whereas the region between 805 and 812 cm⁻¹ represents the tri-s-triazine unit of S-GCN. All these results indicated that the synthesised photocatalyst exhibited good crystallinity and purity. To examine the photocatalytic activity, 0.2 g/L of synthesised S-GCN was immersed in 100 mL of 10 ppm Congo red dye solution, stirred for 25 min, and kept in the dark to establish adsorption–desorption equilibrium followed by open sunlight irradiation. During irradiation, a 3 mL suspension was taken out at intervals of 25 min; absorbance was measured, which decreased with time. Moreover, the S-doped GCN displayed good photocatalytic activity in 150 min of sunlight exposure. The degradation of dyes followed pseudo-first-order kinetics.

2.2. Pristine and Pt-Modified TiO₂ Drive Organic Compound Photodegradation

• Elena-Alexandra Ilie (Săndulescu) ¹, Crina Anastasescu ², Luminita Predoana ², Silviu Preda ², Dana Culita ², Adriana Rusu ², Jeanina Pandele-Cusu ², Ioan Balint ² and Maria Zaharescu ³

¹ 

“Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, Bucharest, 060021, Romania

² 

“Ilie Murgulescu” Institute of Physical Chemistry of the Romanian Academy, 202 Spl. Independentei, 6th district, 060021 Bucharest, Romania

³ 

Romanian Academy, 125 Victoriei Avenue, 1st district, 010071 Bucharest, Romania

Introduction: Sunlight-induced photocatalytic oxidation of organic matter is significant for a number of reasons, including (i) its low cost, (ii) its ability to purify air and water [1], and (iii) its role as an alternative to the selective synthesis of high-value oxygenated compounds [2].

Methods: Materials used: ethanol, TiO₂, and Pt/TiO₂ powders (obtained by sol–gel method). The reaction products of gas-phase oxidation processes were analyzed by gas-phase chromatography (GC-TCD and GC-FID).

Results: Considering light-induced ethanol oxidation on a noble metal (Pt) loaded with TiO₂, both the support and noble metals are crucial for light absorption, charge separation, and carbon dioxide generation. Platinum nanoparticles on TiO₂ can primarily cause the separation of photogenerated charges and a red shift in the light absorption edge.

Conclusions: The light-initiated photo-oxidative routes of an organic substrate over TiO₂ charged with noble metals are revealed in this study. The production of carbon dioxide, the separation of the light-generated charges by platinum addition, and the mechanism of the oxidative conversion reaction of ethanol are the main topics of this analysis of the intricate phenomena connected to the photocatalytic processes.

• References:

2.3. Structural Chemistry and Crystallographic Features of Nb₃Sn Intermetallics

• Taimo Priinits, Artjom Vargunin and Aleksandr Liivand
• Institute of Physics, University of Tartu, 50411 Tartu, Estonia

The use of binary A15 systems as low-Tc superconductors is of great importance for the development of many modern engineering and technological solutions. As a typical representative of this family, we chose the Nb₃Sn system for our structural studies. Our presentation will focus on two main results: The first is the atomic-scale modeling of Nb chain formation in the condensation of the 3:1 binary combination of Nb and Sn atoms. We will discuss reconstruction in the context of the symmetry of the cubic structure, specifically the transformation of the bcc-type superlattice with Im-3m space symmetry and the crystal phases arising along the Im-3m→Pm-3n symmetry-lowering pathway. We argue that, when Nb and Sn are condensed as Nb₃Sn in the Pm-3n cubic structure, the stabilization of the chains of Nb atoms running parallel to the main cubic axis is caused by their periodic off-center displacements. Change in the point symmetry of the Nb positions is a necessary condition for stable charge ordering. The other effect we will discuss relates to the crystallographic orbits of the Nb sites in the Nb₃Sn Pm-3n lattice geometry. The point symmetry microstructure is caused by the 6c→6d shift in the change of occupation of the 6c Wyckoff positions. Such an occupation shift induces the phenomenon of structural modulation between niobium chain orientations and, thus, defines the bulk structure as composed of subsystems, where the orientation of the niobium chains induces anisotropy caused by the distinct chain patterning in the neighboring lattice regions. Translational symmetry of the Pm-3n space group begins to hold only through the partitioned subsystems. This allows us to predict that the crystallographic equivalence in the point symmetry of Nb sites may be removed when the alloy microstructure is assembled as adjacent grains.

3. Session: Microstructure of Metals and Alloys

3.1. Hot Deformation Mechanisms of a Metastable Ti-18Mo Alloy

• Esmaeil Shahryari ¹, Maria Cecilia Poletti ^1,2, Petr Harcuba ³, Josef Stráský ³, Miloš Janeček ³ and Fernando Gustavo Warchomicka ¹

¹ 

Institute of Materials Science, Joining and Forming, Graz University of Technology, Kopernikusgasse 24/I, 8010 Graz, Austria

² 

Christian Doppler Laboratory for Design of High-Performance Alloys by Thermomechanical Processing, Kopernikusgasse 24, 8010 Graz, Austria

³ 

Charles University, Faculty of Mathematics and Physics, Department of Physics of Materials, Ke Karlovu 5, 12116 Prague, Czech Republic

Metastable molybdenum (Mo)-based titanium alloys exhibit a low Young’s modulus, along with excellent biocompatibility, corrosion resistance, and mechanical properties, making them ideal for biomedical applications. The microstructure of Ti-Mo alloys can be tailored through thermomechanical processing, where Mo diffusion significantly influences microstructural evolution. To investigate the deformation mechanisms of a Ti-18Mo alloy, hot compression tests were performed using a Gleeble^® 3800 in both the α+β- and β-phase regions at temperatures ranging from 610 °C to 910 °C and strain rates between 0.01 s⁻¹ and 10 s⁻¹, reaching final strains of 0.50 and 0.80, followed by an immediate water quench. Scanning electron microscopy images and electron backscatter diffraction measurements were used to examine the microstructure of the deformed samples in the α+β- and β-phase regions, respectively. In the β-phase region, the flow curves exhibit a broad work hardening, uncommon in various β-Ti alloys, representing a slowing of dynamic restoration processes, likely due to the influence of Mo on the softening kinetics. Flow curves from α+β-phase deformation show a softening after the peak value, attributed to the globularisation of the α phase. Heterogeneous microstructures were observed during deformation in both regions, indicating that the subgrain formation and α phase globularisation primarily occurred near the previous grain boundaries. Dynamic recovery, dynamic recrystallisation, subgrain size, and α phase globularisation were quantified and correlated with deformation parameters and the influence of Mo.

3.2. Gas Tungsten Arc Welding of As-Cast AlCoCrFeNi2.1 Eutectic High-Entropy Alloy

• Jiajia Shen ¹, Priyanka Agrawal ², J.G. Lopes ³ and J.P. Oliveira ¹

¹ 

CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal

² 

Center for Friction Stir Processing, Department of Materials Science and Engineering, University of North Texas, Denton, TX 76207, USA

³ 

UNIDEMI, Department of Mechanical and Industrial Engineering, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal

AlCoCrFeNi2.1 eutectic high-entropy alloy stands out for its remarkable mechanical properties, offering an excellent balance between strength and plasticity. For the first time, gas tungsten arc welding (GTAW) was applied to this as-cast alloy to investigate its weldability and associated microstructural evolution. A comprehensive analysis of the welded joint’s microstructure was performed using electron microscopy, electron backscatter diffraction (EBSD), synchrotron-based X-ray diffraction (SXRD), and thermodynamic simulations. The alloy’s mechanical properties were characterized through microhardness mapping and tensile testing, which was integrated with digital image correlation (DIC) to provide insights into local deformation behavior. The welded joint, comprising the base material (BM), heat-affected zone (HAZ), and fusion zone (FZ), retained a eutectic structure with FCC and B2-type BCC phases. Variations in phase proportions arose due to thermal cycling during welding. BCC nanoprecipitates present in the BM were partially dissolved near the FZ boundary within the HAZ. Grain refinement in the FZ, driven by rapid solidification, contributed to increased hardness in this region. Despite these microstructural changes, tensile testing showed that the joints exhibited a favorable balance between strength and ductility, with failure consistently occurring in the BM. This work highlights the feasibility of using arc-based welding methods for high-entropy alloys, underscoring their potential for advanced structural applications.

4. Session: Entropic Alloys and Meta-Metals

Impact of B₄C on Phase Transformation and Mechanical Behavior in Metastable High-Entropy Alloys

• Isaque Moura ¹, Giovani Gonçalves Ribamar ², Jiajia Shen ² and João Pedro Oliveira ²

¹ 

UNIDEMI—NOVA School of Science and Technology (FCT NOVA), Portugal

² 

i3N/CENIMAT—NOVA School of Science and Technology (FCT NOVA), Portugal

Metastable high-entropy alloys (HEAs) represent a significant advancement in material science, addressing the longstanding challenge of balancing strength and ductility in alloys. The study of metastable HEAs offers a valuable framework for exploring the influence of γ-f.c.c.→ε-h.c.p. phase transformations on mechanical performance, particularly concerning volumetric changes during deformation. Structural changes, such as variations in the c/a ratio, provide critical insights into the interplay between phase stability and mechanical behavior in HEAs. We investigated the microstructure, mechanisms underlying phase transformations, and mechanical behavior of metastable Fe₄₀Mn₂₀Co₂₀Cr₁₅Si₅ and Fe₄₀Mn₂₀Co₂₀Cr₁₅Si₅ + 0.25wt.% B₄C HEAs fabricated via laser powder bed fusion (LBPF). Special attention was given to comparing how the presence of B₄C affects phase transformations, including variations in the c/a ratio, volumetric changes, and overall phase stability during deformation. The HEAs without B₄C demonstrated an increase in the c/a ratio, primarily due to a significant expansion of the c-axis, while introducing B₄C altered this response, leading to a decrease in the c/a ratio. This reduction was driven by a contraction of the c-axis rather than an expansion. Furthermore, the a-axis remained unchanged for both alloys. The contrasting behaviors highlight how adding B₄C fundamentally alters the stress-induced dimensional changes during the γ-f.c.c.→ε-h.c.p. phase transformation.

5. Session: Metallic Functional/Electronics Materials

5.1. Analysis of the Capture of Microplastics with Hydrophobic Metallic Particles

• J.J. Suñol ¹, Lluisa Escoda ² and Asma Wederni ²

¹ 

University of Girona, 17003 Girona, Spain

² 

Department of Physics, University of Girona, 17003 Girona, Spain

One of the main environmental problems is related to the generation of micro- and nanoplastics. This study aims to analyze the viability of an innovative method consisting of the adsorption of microplastics using hydrophobic metal particles, which require their functionalization. A laboratory protocol (of the adsorption process) and analysis (of the particles and the adsorption efficiency) were designed. For the production of the metal particles (of micrometric size), the ball milling technique was used. Also, milling equipment operating with liquid nitrogen was used to generate the microplastics. For morphological characterization, electron microscopy was used; for structural X-ray diffraction to analyze the composition, X-ray dispersion spectroscopy was used; and to monitor the functionalization, Fourier transform infrared spectroscopy was used. The functionalization was carried out in a 1 M solution of lauric acid. The metallic particles are nanocrystalline (crystallite size range of 12–44 nm) and the crystallographic phase is the bcc-Fe. It was found that the adsorption of microplastics is more efficient when the size of the metal particles is smaller. The correct functionalization of the metal particles prevents their oxidation in aqueous media. Regarding the efficiency in the capture of microplastics, the highest value found is close to 90%, depending on the metallic particle production conditions. Additional studies are needed to optimize the efficiency of microplastic capture, probably by increasing the surface/volume ratio of metal particles.

5.2. Cobalt-Based Electrocatalysts: A Pathway Toward Cost-Effective and High-Performance Energy Conversion

• Huma Amber ¹, Aldona Balčiūnaitė ², Loreta Tamasauskaite-Tamasiunaite ², Zita Sukackienė ², Jūratė Vaičiūnienė ² and Eugenijus Norkus ²

¹ 

Department of Catalysis, Center for Physical Sciences and Technology (FTMC), Lithuania

² 

Department of Catalysis, State Research Institute Center for Physical and Technological Sciences (FTMC), Lithuania

The significant demand for sustainable and cost-effective energy solutions has led to extensive research into non-noble and earth-abundant metal-based electrocatalysts for energy conversion reactions, such as hydrogen evolution reactions (HERs). While noble metals such as platinum (Pt) and iridium (Ir) have historically dominated due to their exceptional catalytic performance, palladium (Pd) has emerged as a compelling alternative. This is primarily due to its comparatively lower cost, excellent hydrogen adsorption and desorption properties, high catalytic activity, and improved durability. Recent strategies, such as Pd-based alloying with non-noble metals (e.g., Ni, Co, Mo) and nanostructuring techniques, have resulted in enhanced catalytic performance, greater active site exposure, and better stability in alkaline conditions. Herein, cobalt–phosphorus (CoP) and cobalt–iron–phosphorus (CoFeP) coatings were deposited on the copper (Cu) substrate using an electroless deposition method. The incorporation of Pd nanoparticles on the CoP and CoFeP coatings using the galvanic displacement method has been shown to enhance the catalytic activity of the coatings. The morphology, structure, and composition of the catalytic materials were thoroughly examined using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and inductively coupled plasma optical emission spectroscopy (ICP-OES). Moreover, the electrocatalytic activity of the catalysts for the HER in an alkaline solution (1 M KOH) was studied using linear sweep voltammetry (LSV). Electrochemical measurements revealed that PdCoFeP exhibited superior HER activity with a lower overpotential of 180 mV at 10 mA cm⁻² compared to PdCoP due to synergistic effects between Pd, Fe, and Co, which promote efficient charge transfer and reduce the reaction overpotential. This work highlights that Pd-based non-noble metal electrocatalysts have the potential to accelerate the transition towards sustainable hydrogen production, thus contributing to the broader goal of clean and renewable energy technologies.

• Acknowledgement: This research was funded by a grant (No. P-MIP-23-467) from the Research Council of Lithuania.

5.3. Innovation in Manufacturing Technologies with Eco-Sustainable Magnetic Materials

• J.J. Suñol ¹, Asma Wederni ¹, Jason Daza ¹ and Lino Montoro ²

¹ 

Department of Physics, University of Girona, 17003 Girona, Spain

² 

EMCI Department, University of Girona, 17003 Girona, Spain

In the field of permanent magnets, there is growing interest in additive manufacturing techniques and, in terms of materials, in recycling rare earth elements. In collaborative projects (Magneco CPP2023-010653, Llavor-0005) between the university and industry, permanent magnets have been synthesized using stereolithography or pellet extrusion. Additive manufacturing techniques favor the efficient creation of complex components, reducing costs and production times, improving quality, and allowing greater customization in diverse industries such as aerospace, the automotive industry, and renewable energy. In the industrial field, the creation/generation of optimized and sustainable designs for permanent magnets is expected, reducing dependence on rare earth elements and recycling obsolete materials, as well as new sustainable and scalable manufacturing processes. It is a project in development in which the optimization of processes and materials shows the need for interaction between academia and companies, requiring the complete characterization (morphological, compositional, chemical, mechanical, thermal, magnetic) of both materials and components. One of the problems to be avoided is the oxidation of recycled powder particles, which makes their reconditioning necessary. Regarding the components, the achievement of sufficient densification and magnetic response (saturation magnetization, coercivity) is necessary. The influence of the controlled application of an external magnetic field (assisted magnetic field and additive manufacturing) is also analyzed during the manufacturing process.

5.4. Mechanism and Analysis of Orange Peel Formation on Bent Thin-Walled Copper Tubes

• Yan Zhou ¹, Songwei Wang ¹, Hongwu Song ¹, Zhongtao Zhang ² and Zhengyuan Gao ³

¹ 

Shi-Changxu Innovation Center for Advanced Materials, Institute of Metal Research, Chinese Academy of Sciences

² 

Golden Dragon Precise Copper Tube Group Inc.

³ 

School of Electrical and Mechanical Engineering and Vehicle Engineering, Chongqing Jiaotong University

Thin-walled pure copper tubes, extensively used in high-heat-flux electronic devices due to their excellent thermal conductivity, often develop orange peel defects during bending processes. This study compares tube samples with and without orange peel defects by analyzing their macro-surface morphology and microstructural evolution before and after bending. The crystal plasticity finite element model (CPFEM) was developed to explore the correlation between crystallographic orientation and surface defects. Finally, a multi-scale model of the tube bending process was developed by integrating the macroscopic finite element method (FEM) with the visco-plastic self-consistent (VPSC) approach to simulate and analyze the formation of orange peel defects on the outer wall of the tube at the bending site. The results indicate that high-temperature sintering causes significant grain coarsening and pronounced recrystallization textures in the matrix. Samples exhibiting orange peel defects contain banded annealing twins with textures distinct from the matrix, characterized by low Schmid factors and poor plastic deformation compatibility. CPFEM simulations demonstrate that during uniaxial stretching, “soft-oriented” matrix grains experience negative displacement along the surface normal, forming depressions, whereas “hard-oriented” grains undergo positive displacement, generating protrusions. This mismatch in localized deformation results in the formation of the macroscopic orange peel morphology. Simultaneously, the VPSC simulation results reveal that the number of activated slip variants differs between tubes with and without orange peel defects. Tubes with defects exhibit fewer activated slip variants and experience greater resistance to deformation.

5.5. Metallic and Half-Metallic Properties of Full Heusler Alloy Co2MnGa with Antisite Defects

• Evgeniy D. Chernov and Alexey V. Lukoyanov

¹ 

M.N. Mikheev Institute of Metal Physics, Ural Branch, Russian Academy of Sciences, S. Kovalevskaya Str., 18, 620108 Ekaterinburg, Russia

² 

Institute of Physics and Technology, Ural Federal University, Mira Str., 21, 620002 Ekaterinburg, Russia

Heusler compounds are attracting tremendous attention due to their significant magnetoresistance, half-metallicity, and other properties which are used in spintronics, magnetooptical, memory devices, etc. [3]. We performed first-principal calculations for compound Co₂MnGa, taking into consideration antisite structural defects. Co₂MnGa without antisite defects was confirmed to be a topological Weyl compound. The exact electronic states at E Fermi are 1.8 st./eV/f.u. in the majority spin and 0.58 st./eV/f.u. in the minority spin. Hence, the spin polarization is 52%. The magnetic moments are 0.73 (Co) μ_B, 2.91 (Mn) μ_B and −0.15 (Ga) μ_B, and the total moment of Co₂MnGa is 4.22 μ_B, which is in good agreement with the experimentally reported moment of 4.05 μ_B, which corresponds to the accuracy of our theoretical calculation being as high as 96%, it was previously calculated to be between 3.07 and 4.21 μ_B [3]. For the Co1-Mn antisite defect, the magnetic moment decreases to 1.07 μ_B; for the Co2-Ga replacement, the magnetic moment is 1.85 μ_B. However, for the Co2-Mn antisite replacement, the total magnetic moment reaches up to 5.89 μ_B. Thus, the antisite defects in Co₂MnGa result in different changes in the magnetic moments and metallic properties, following from the densities of electron states calculated in our study.

• Elphick, K.; Frost, W.; Samiepour, M.; Kubota, T.; Takanashi, K.; Sukegawa, H.; Mitani, S.; Hirohata, A. Heusler alloys for spintronic devices: review on recent development and future perspectives. Sci. Technol. Adv. Mater. 2021, 22, 235–271. https://doi.org/10.1080/14686996.2020.1812364.

5.6. Modified Sol–Gel Synthesis of SiO₂ Nanoparticles

• Omar Mahmoud ¹, M’Hamed Guezzoul ², Abdelkader Nebatti Chergui ³, Moumene Taqiyeddine ⁴, El Habib Belarbi ⁴, Hafida Miloudi ¹ and Djamila Bouazza ¹

¹ 

Laboratory of Chemistry of Materials, University of Oran 1, Algeria

² 

Laboratory of Materials (LABMAT), National Polytechnic School of Oran Maurice Audin (ENPO-MA), Algeria

³ 

Laboratory of Materials Sciences and Applications (LSMA), University of Ain Temouchent Belhadj Bouchaib, Faculty of Sciences and Technology, Algeria

⁴ 

Laboratory of Synthesis and Catalysis, University of Tiaret, Algeria

In this study, we successfully synthesized silicon nano-dioxide by modifying the conventional sol–gel method, eliminating the use of water as a hydrolysis agent and using oxalic acid as a reagent and structural reaction agent. The analytical results reveal that the product has a high purity and a coherent molecular structure. X-ray diffraction (XRD) analysis revealed a broad peak with an angle of 22.5°, indicating the morphosyntactic structure. Fourier transform infrared spectroscopy (FTIR) confirmed the presence of silicon dioxide bonds, while atomic force microscopy (AFM) revealed significant differences in surface morphology. In contrast to the typical spherical shape of silicon nano-dioxide, the surface of the synthesized silicon dioxide shows a mountainous terrain with marked peaks and valleys, with the distance between the lowest and highest points being less than 10 nanometers, indicating the small size of the nanocrystals. Ultraviolet (UV) spectroscopy revealed a distinct peak at a wavelength of 266 nm, corresponding to a small energy gap of 3.8 electron volts. This result shows that the synthesized solid has a semi-conductive character, unlike conventional silicon oxides, which are characterized by their insulating properties. Additionally, the unique morphology of the synthesized silicon dioxide nanoparticles suggests potential applications in various fields such as electronics, photonics, and catalysis. The modified sol–gel method employed in this study offers a novel approach to synthesizing silicon dioxide nanoparticles with tailored properties, paving the way for future research and development in nanotechnology.

5.7. Ultrasonic Powder Atomization of Raney Nickel-Type Precursors for Hydrogen Cathodes in Water Electrolysis

• Niclas Hanisch ¹, Thomas Lindner ¹, Sophie Costil ², Linto George Thomas ¹, Hanlin Liao ² and Thomas Lampke ¹

¹ 

Materials and Surface Engineering Group, Institute of Materials Science and Engineering, Chemnitz University of Technology, D-09107 Chemnitz, Germany

² 

ICB-LERMPS UMR6303, Univ. Bourgogne Franche-Comté, UTBM, F-90100 Belfort cedex, France

Hydrogen, as an emission-neutral energy carrier, plays a key role in establishing a circular energy system and holds the potential to decarbonize numerous technical sectors. However, most hydrogen production to date has been derived from fossil fuels such as gray hydrogen. In contrast, sustainable green hydrogen can be generated by water electrolysis using renewable electrical energy. Yet, this remains economically unviable due to the comparatively low efficiency and high costs of precious cathode materials such as platinum. Hence, Raney nickel-type cathodes present a cost-efficient alternative due to their catalytic material properties. In perspective, thermally sprayed precursors are promising thanks to their characteristic open-porous structure, which is beneficial in applications such as atmospheric plasma spraying. Subsequent leaching of aluminum-rich phases chemically activates the surface and a nickel structure with a high specific surface area remains, which will enhance cathode reactivity. Prior to spraying, however, an appropriate powder feedstock must be identified. Also, the production by powder atomization is to be evaluated in order to meet the requirements for the indented application, including chemical homogeneity and composition, powder morphology and microstructure, phase formation, as well as particle size distribution. Therefore, in this study, preselected metal wires were arc-melted to rods with various compositions and subsequently ultrasonically atomized. Furthermore, bulk specimens were produced by spark-plasma sintering with low oxidation and low porosity. The material properties were examined along this process chain and related to the required functional properties, providing a comprehensive assessment of this approach.

6. Session: Additive Manufacturing

6.1. Friction Stir Welding of Laser Powder Bed Fusion Additively Manufactured Aluminum and Copper Alloys

• Mohammad Abankar, Vincenzo Lunetto, Franco Lombardi, Manuela De Maddis and Pasquale Russo Spena
• Department of Management and Production Engineering, Politecnico Di Torino, Corso Duca Degli Abruzzi 24, 10129 Turin, Italy

This study examines the feasibility of using friction stir welding (FSW) to join laser powder bed fusion (LPBF) additively manufactured Scalmalloy^®, A20X, and CuNiSiCr copper alloys. Additively manufactured aluminum and copper alloys are highly valued for their ability to produce complex geometries. However, challenges such as printability issues, defect management, and the limited production volumes achievable with standard LPBF machines contribute to hindering their large-scale adoption. Consequently, researchers are increasingly exploring welding techniques for joining additively manufactured components. While fusion welding introduces challenges related to melting and solidification, solid-state welding methods like FSW offer significant advantages by preserving the engineered microstructures of these materials.

This research investigates the effects of FSW on the quality of butt joints made from 4 mm thick LPBF-manufactured plates of A20X, Scalmalloy^®, and CuNiSiCr. A range of rotational and welding speeds was tested to evaluate the influence of the joining process on the mechanical properties and microstructures of these alloys. For the aluminum alloys, FSW produced welds with refined microstructures and only minimal reductions in mechanical strength compared to the base material. In contrast, the CuNiSiCr alloy demonstrated an increase in strength after welding, attributed to the fine-grained microstructure in the stir zone compared to the coarse-grained base material. Furthermore, 3D X-ray computed tomography revealed that metal stirring during the FSW process significantly reduced the intrinsic porosity across all the tested alloys. The study also evaluated hardness profiles, joint appearance, and fractographic analyses, highlighting a strong correlation between microstructural features and mechanical performance. These findings underscore the potential of FSW as an effective joining method for LPBF-manufactured components.

6.2. Development of New Stainless Steel via Laser Powder Bed Fusion Process

• Sanae Tajalli Nobari ¹, Alireza Moradi ², Amir Behjat ³, Mohammad Taghian ⁴, Luca Iuliano ³ and Abdollah Saboori ⁴

¹ 

Department of Applied Science and Technology, Politecnico di Torino, Corso Duca Degli Abruzzi 24, 10129 Torino, Italy

² 

Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca Degli Abruzzi 24, 10129 Torino, Italy

³ 

Department of Management and Production Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy

⁴ 

Integrated Additive Manufacturing Center (IAM@PoliTo), Politecnico di Torino, Corso Castelfidardo 51, 10129 Torino, Italy

Laser Powder Bed Fusion (L-PBF) is one of the most important metal additive manufacturing (AM) methods, with various applications in industries such as the medical and automotive sectors, where precision and customization are essential. This research emphasizes integrating machine learning (ML) techniques with experimental analyses to optimize L-PBF processes. It provides critical insights into the interplay among process parameters, microstructure, and mechanical performance. This study employs ML to model the relationship between process parameters and relative density in AISI 316L stainless steel components containing 2.5% copper, produced via L-PBF. Support Vector Regression (SVR) was identified as the most precise algorithm for predicting relative density, with an accuracy of over 99%, enabling the optimization of process parameters to achieve desired outcomes such as high density, improved surface quality, or enhanced productivity. Subsequently, microstructural and mechanical properties were analyzed to provide deeper insights into material behavior. Microstructural investigations using Scanning Electron Microscopy (SEM) and Optical Microscopy (OM) revealed substantial transformations, including forming equiaxed and columnar cells attributed to copper addition. Irregular grains were observed, resulting from the rapid solidification characteristic of the L-PBF process. Notably, copper fully dissolved into the austenitic phase with no evidence of segregation, leading to increased lattice distortion, reduced crystallite size, and enhanced hardness. Melt pool dimensions were analyzed across samples with varying process parameters, establishing correlations with porosity levels and microstructural refinement. Additionally, in-situ alloying with copper was found to improve mechanical properties slightly. Tensile testing further explored the relationship between porosity and mechanical properties, providing a comprehensive understanding of the impact of process parameters and material composition on overall performance. SEM analysis of the fracture surfaces identified both brittle and ductile failure mechanisms. Brittle fractures exhibited quasi-cleavage planes, likely aligning with melt pool boundaries, while ductile fractures displayed extensive dimple networks.

6.3. Machine Learning-Assisted Material Development via Laser Powder Bed Fusion Process

• Alireza Moradi ¹, Sanae Tajalli ², Amir Behjat ^3,4, Mohammad Taghian ^3,4, Luca Iuliano ^3,4 and Abdollah Saboori ^3,4

¹ 

Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Corso Duca Degli Abruzzi 24, 10129 Torino, Italy

² 

Department of Applied Science and Technology, Politecnico di Torino, Corso Duca Degli Abruzzi 24, 10129 Torino, Italy

³ 

Department of Management and Production Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy

⁴ 

Integrated Additive Manufacturing Center (IAM@PoliTo), Politecnico di Torino, Corso Castelfidardo 51, 10129 Torino, Italy

Metal additive manufacturing (AM) revolutionized the fabrication of complex metal components, providing remarkable precision and flexibility in producing complex geometries. Integrating artificial intelligence (AI) can further revolutionize this field by highlighting complex relationships within manufacturing systems and enhancing quality control. Machine learning (ML) methods provide innovative solutions to optimize resource consumption, improve process efficiency, and address manufacturing challenges by correlating process parameters, material properties, part geometry, microstructural characteristics, and their resultant properties. In metal AM processes, ML applications extend beyond process optimization to include defect detection, in situ monitoring, and the enhancement of manufacturability and repeatability of components. This study optimizes key process parameters in laser powder bed fusion (L-PBF) to correlate the processing parameters and defect content in AISI 316L-2.5%Cu components. By applying ML algorithms, this research identifies optimal process parameter combinations to achieve specific objectives such as high production rate, low defect content, or superior surface quality. Seven ML algorithms (Bayesian Regression, Decision Tree Regression, Gradient Boosting Regression, Gaussian Process Regression, K-Nearest Neighbors Regression, Random Forest Regression, and Support Vector Regression) were systematically evaluated for their predictive accuracy across varying training and testing dataset sizes. Support Vector Regression (SVR) with a training size of 80% was chosen as the most accurate model for relative density prediction, with an average error of 0.62%. The optimized process parameters, derived from the best-performing ML model prediction, demonstrated a precise relationship between process parameters and defect content for achieving relative density values above 99.5% or high productivity. The optimized parameters obtained from this approach highlight the potential of ML-driven methodologies to balance productivity and defect content in AM processes. These findings demonstrate the importance of ML in advancing L-PBF technology and its broader applicability in metal AM.

6.4. Electroless Nickel Plating of Microglass Balloons (MGBs)

• Rajkishore Singh, Tahir Hussain Deader, Anand kumar subramaniyan and Rajkumar Velu
• Department of Mechanical Engineering, IIT Jammu, India

This study presents a thorough exploration of borosilicate microglass balloons (MGBs) with a focus on their potential application in aerospace engineering. The research encompasses the preparation, characterization, and modification of MGBs utilizing advanced techniques aimed at enhancing their functionality and performance within aerospace composite materials. Initial efforts involved the synthesis of MGBs according to established protocols, followed by meticulous characterization employing Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS). SEM analysis provided insights into the particle size distribution, with a particular emphasis on the AlSi10Mg alloy, revealing an average size of 35 µm. Concurrent EDS examination confirmed the elemental composition of the alloy. Subsequent utilization of MGBs as reinforcement within the AlSi10Mg matrix revealed an average particle size of 75 µm, with EDS analysis identifying key constituent elements, including Si, O, Na, Ca, and Au. To further enhance the properties of MGBs, systematic surface treatments were conducted under varying chemical compositions and temperatures, guided by Taguchi methods. Post-treatment SEM analysis demonstrated a notable reduction in average particle size to 60 µm, corroborated by EDS analysis of the altered chemical makeup. Fourier Transform Infrared (FTIR) spectroscopy provided valuable insights into the formation of essential chemical bonds, particularly C-C and C-O bonds, indicative of improved covalent bonding and mechanical properties. Additionally, activation treatments were implemented to introduce functional groups onto the MGB surface, as confirmed by SEM analysis, revealing a particle size distribution averaging 75 µm. EDS analysis further detected the presence of catalytic elements such as Cu, Ag, and Bi, contributing to enhanced layer adhesion. FTIR analysis confirmed the establishment of crucial C-O and CH3 bonds, significantly augmenting surface wettability and adhesion properties.

6.5. Material Anisotropy of Non-Heat-Treated Inconel 718 Additively Manufactured by Wire Arc Additive Manufacturing

• Shinichiro Ejiri
• Nikkiso Co., Ltd., 189-8520 Tokyo, Japan

Material anisotropy is an important topic to consider when using additive manufacturing for industrial applications. Since the products fabricated by wire arc additive manufacturing (WAAM), a metal additive manufacturing technology used to fabricate large parts, are sometimes used in parts that require a specific level of strength required by industry, it is essential to clarify the characteristics of these products for their industrial application. Furthermore, it should be noted that the fabrication of complex shapes such as blades by WAAM cannot be used for industrial applications, because of defective fabrication if appropriate fabrication conditions are not used. However, many studies have focused on simple shapes such as flat plates; thus, there is a problem in that evaluations have not always been conducted under conditions that enable the fabrication of complex shapes. In this study, an investigation was conducted into the material anisotropy of Inconel 718 under conditions where impeller blades can be fabricated by WAAM. An Inconel 718 wall was fabricated by WAAM, and tensile specimens were cut from the wall. Two different directions were used for the cutout: vertical and horizontal. Tensile tests were performed using these two types of specimens with different cutout directions. A comparison of the tensile test results showed that the difference between tensile strength and elongation at break was less than 3%. This indicates that the material anisotropy of Inconel 718 without heat treatment is small compared to other materials additionally produced by WAAM.

6.6. Mechanical Properties of SST316L and Inconel 718 Multi-Material Additively Fabricated by Wire Arc Additive Manufacturing with Heat Treatment

• Shinichiro Ejiri
• Nikkiso Co., Ltd., Tokyo 189-8520, Japan

One approach to improving the manufacturing technology of turbomachinery is the application of metal additive manufacturing. Several studies have shown that wire arc additive manufacturing (WAAM) can be used to improve fabrication and reduce the environmental impact of impellers and other components with blades. To further advance manufacturing technology using WAAM, it is necessary to evaluate not only additive manufacturing using a single material, but also additive manufacturing combining multiple materials. However, there are only a limited number of examples of such studies. Therefore, there is a problem in that sufficient knowledge for industrial applications has not yet been obtained. The objective of this study is to evaluate the mechanical properties of a multi-material, stainless steel SST316L and nickel-based alloy, Inconel 718, fabricated by WAAM, when applied with heat treatment. To fabricate the test piece, a wall combining the two materials was fabricated by additively manufacturing an Inconel 718 wall made via WAAM and then additively manufacturing a SST316L wall on top of the Inconel 718 wall made via WAAM. A test piece was obtained by cutting out tensile test specimens from the wall. The specimens were subjected to several types of heat treatments and tensile tests were performed to analyze differences in their mechanical properties. The heat treatments were solution heat treatment, which is generally used for austenitic stainless steels, and aging treatment, which is generally used for Inconel 718. As a result, it was found that the multi-material under any of the heat treatments has mechanical properties that can be concluded to be industrially applicable.

6.7. Optimization of Laser Powder Bed Fusion Parameters for Scalmalloy: Enhancing Print Quality and Mechanical Performance for Space Electronic Packaging

• Kedarnath Rane ¹, Andrew Bjonnes ¹, Ashfaq Mohammad ¹, Sampan Seth ¹ and Iain Bomphray ²

¹ 

Digital Factory, National Manufacturing Institute Scotland, 3 Netherton Sq, Paisley, Renfrew, UK

² 

Lightweight Manufacturing Centre, National Manufacturing Institute Scotland, Paisley, Renfrew, UK

Scalmalloy, an aluminum–magnesium–scandium alloy, is renowned for its exceptional strength-to-weight ratio and high ductility, making it a prime candidate for aerospace and space applications. This study focuses on optimizing the Laser Powder Bed Fusion (L-PBF) process parameters to enhance the print quality and mechanical properties of Scalmalloy components tailored for space electronic packaging applications where precise complex wall geometries and shape stability are crucial.

Employing Design of Experiments methodologies, we systematically varied key process parameters, including layer height, laser power, scanning speed, and hatch spacing. Standardized cubic specimens were fabricated across a range of energy densities to establish correlations between process parameters, porosity levels, and mechanical strength. Comprehensive analyses were conducted to evaluate the performance of these specimens. Our findings indicate that an optimal energy density window of 90 to 125 J∙mm⁻³ minimizes porosity while maximizing mechanical performance.

Utilizing these optimized parameters, we designed and developed prototype components intended for space applications, emphasizing lightweight structures, thermal stability, and structural integrity. The results demonstrate that precise control of L-PBF parameters facilitates the production of Scalmalloy parts with superior mechanical properties and minimal defects, aligning with the stringent requirements of space applications. This research underscores the significance of parameter optimization in additive manufacturing to achieve resource-efficient production of high-performance metallic components.

6.8. Performance Analysis of Ni-Doped SS316L Electro-Catalysts Synthesized via Wire Arc Additive Manufacturing (WAAM)

• Somnath Nandi and Manidipto Mukherjee
• AMRG, CSIR-CMERI, Durgapur, West Bengal, 713209

India aims to produce five million tonnes of green hydrogen annually by 2030, which has ignited significant research into developing efficient and cost-effective production methods. Electrolysis, a critical environmentally friendly method for producing green hydrogen, faces challenges due to its reliance on costly precious metal electrodes, making it both expensive and inefficient. To reduce hydrogen production costs, this study investigates using wire arc additive manufacturing (WAAM) to create a Ni-induced Fe-Ni bimetallic structure (BS) as a cost-effective, alternative, and sustainable catalyst for efficient green hydrogen production. WAAM is an emerging technique that enables the deposition of multiple materials, such as stainless steel (SS) and nickel (Ni), layer by layer to create a BS with tailored properties.

The research focuses on the design and optimization of a BS by depositing different compositions of Ni (10% to 40%) in SS316L. The mechanical, metallurgical, and corrosion properties with oxygen evolution reaction (OER) activities were evaluated using corrosion, electrolysis, X-ray diffraction, and scanning electron microscopy.

This study revealed that increasing Ni content reduces micro-hardness by up to 38.14% due to higher L10-FCC phase formation. Similarly, increasing Ni content reduced the OER and corrosion activity, except for the 40% Ni content sample due to intermetallic formation (IMC) and lower polarization resistance. Further quenching heat treatment of the 40% Ni sample exhibited more remarkable performance than all other samples.

Finally, we have come to understand the effectiveness of WAAM in fabricating Ni-doped SS316L electrodes in an affordable way. IMC formation enhanced the activity of 40% Ni, and heat treatment plays a critical role in OER performance. Future work will explore other composition variations to understand the electrochemical behavior further, aiming to develop a scalable, cost-effective method for manufacturing green hydrogen-energy fuel-cell electrodes.

7. Session: Corrosion, Wear, and Protection

7.1. PMMA–Siloxane–Silica Coating to Enhance Corrosion Resistance of AZ31

• Nina Kovač ^1,2, Slavko Kralj ³, Ingrid Milošev ¹, Barbara Kapun ¹ and Peter Rodič ¹

¹ 

Jožef Stefan Institute, Department of Physical and Organic Chemistry, Jamova c. 39, 1000 Ljubljana, Slovenia

² 

Jožef Stefan International Postgraduate School, 1000 Ljubljana, Jamova c. 39, Slovenia

³ 

Jožef Stefan Institute, Department for Materials Synthesis, Jamova c. 39, 1000 Ljubljana, Slovenia

Several studies in biomedicine have demonstrated the advantages of biodegradable and biocompatible metals for temporary implants, as they naturally degrade within the body, eliminating the need for surgical removal. Among them, magnesium–aluminium–zinc alloys, such as AZ31, show potential for controlled degradation in physiological environments, but their primary limitation is their rapid degradation [4]. This accelerated corrosion compromises implant integrity, leading to premature failure and limiting clinical applications. Thus, effective protective strategies are essential to enhance their corrosion resistance.

This study aimed to (a) perform a surface pretreatment to improve adhesion between the protective coating and the AZ31 alloy, and (b) develop a PMMA–siloxane–silica coating to reduce degradation. The formulation, based on 3-(methacryloyloxy)propyl trimethoxysilane and methyl methacrylate, was optimized for enhanced protective properties [5]. Its synthesis was characterized using real-time Fourier transform infrared spectroscopy, while its surface morphology and composition were analyzed via scanning electron microscopy and energy-dispersive spectroscopy. Corrosion resistance was evaluated through immersion tests in simulated body fluid (SBF) using potentiodynamic polarization and electrochemical impedance spectroscopy. Additionally, degradation behaviour was evaluated by monitoring pH variations and hydrogen evolution in SBF over time.

The results confirm that the PMMA–siloxane–silica coating significantly enhanced AZ31 corrosion resistance, ensuring controlled degradation. These findings present the potential of siloxane–silica coatings for biomedical applications.

• Acknowledgements: Financial support was provided by the Slovenian Research and Innovation Agency (ARIS) under research core funding P1-0134, P2-0393 and P2-0089 and through the ARIS project J2-60047.

7.2. Corrosion Behavior of Biodegradable Mg-Zn-Ca Alloy Under Simulated Severe Post-Implantation Inflammatory Conditions

• Sara Bahrampour ¹, Aydin Bordbar-Khiabani ², M. Hossein Siadati ¹, Michael Gasik ² and Masoud Mozafari ³

¹ 

Faculty of Materials Science and Engineering, K. N. Toosi University of Technology, Tehran, Iran

² 

Department of Chemical and Metallurgical Engineering, School of Chemical Engineering, Aalto University, Espoo, Finland

³ 

Research Unit of Health Sciences and Technology, Faculty of Medicine, University of Oulu, Oulu, Finland

Magnesium alloys are promising candidates for temporary implant materials due to their biocompatibility, biodegradability, and ability to support tissue regeneration while gradually dissolving in physiological environments. However, the inflammatory environment near implants, characterized by the presence of reactive species and acidic conditions, can significantly influence their corrosion behavior. This study investigates the electrochemical corrosion performance of Mg-2.1wt% Zn-0.6wt% Ca alloy in three simulated physiological conditions: (1) normal medium (phosphate-buffered saline, pH 7), (2) inflammatory medium (PBS with H₂O₂ and HCl, pH 5), and (3) severe inflammatory medium (PBS with H₂O₂, HCl, bovine serum albumin [BSA], and lactic acid, pH 3).

Electrochemical tests, including potentiodynamic polarization and electrochemical impedance spectroscopy, were employed to systematically evaluate the corrosion rates and underlying mechanisms of the alloy in the three simulated media. The results demonstrated that the presence of H₂O₂ and an acidic pH significantly accelerated the corrosion rate of the Mg-Zn-Ca alloy, owing to the oxidative stress induced by H₂O₂, which promoted the formation of reactive oxygen species (ROS) that destabilized the magnesium hydroxide protective layer. The acidic pH further exacerbated the corrosion by dissolving the passivating Mg(OH)₂ layer, exposing fresh magnesium to the corrosive medium.

In addition, the inclusion of BSA and lactic acid in the severe inflammatory medium amplified the corrosion process. BSA, a protein that simulates the role of extracellular proteins, binds to the alloy surface and alters the local electrochemical environment by forming complexes with magnesium ions. This chelation effect destabilizes the surface and promotes ion release. Similarly, lactic acid, a byproduct of cellular metabolism during inflammation, acts as a weak organic acid that enhances the dissolution of magnesium hydroxide through acidification and ion chelation mechanisms. Together, BSA and lactic acid simulate conditions that reflect the inflammatory response and metabolic activity near implants, highlighting their synergistic impact on accelerating corrosion.

7.3. Methodological Routes for Failure Analysis in Continuous Rods for Artificial Lift Systems: A Data-Driven and Damage Characteristic Approach

• Andrés Fernando Quintana Rondón, Jose Miguel Jiménez Martínez, Giovanni Juzga and Jorge Hernando Panqueva
• Corporación para la Investigación de la Corrosión, Km 2 Vía Refugio Sede UIS Guatiguará, Piedecuesta, Santander, Colombia

One of the key components in the reciprocating lift system and progressive cavity pump system is the steel rod string. This part is in charge of two main objectives in oil production. First, it allows the transmission of movement from surface to downhole, and secondly, it permits fluid lift. Nowadays, the use of continuous rods instead of conventional coupling rod systems has gained considerable attention due to its advantages like the higher amount of annular space available for production, less complex installation, and better distribution of contact loads with tubing. Understanding the reasons for continuous rod failure important to improve the performance and propose improvements in its design, use, and materials. Herein, an extensive data analysis of 51 failures in continuous rods has been performed, providing principal insights to identify the damage mechanisms, and, through fractography analysis, the principal service loads are identified. All the analyzed failures have occurred due to fatigue, implying that fatigue design and assessment are necessary for successful rod performance. Stress concentrators have been caused due to abrasion related to sand management, friction between the tubing and the rod, corrosion (CO₂, microorganisms), issues with rod manufacture quality, operative conditions, installation, and synergies between them. Our results show that the three main reasons for failure are corrosion (31.4%), fretting corrosion (13.4%), and abrasion–corrosion (11.8%) which are related to service conditions, and their principal morphological features were identified. Also, manufacturing rod quality is the source of 9.8% of failures. This provides a useful guide for engineers to find an easy way to identify the reasons for failure in their oilfields. Finally, a comprehensive analysis of the principal used metallurgies is presented, presenting their main advantages, limitations, quality control benchmarks, and future perspectives for new materials in this component.

7.4. Microbial Corrosion in Oil Transportation and Storage Systems: Laboratory-Scale Study on Biofilm and Pitting Formation

• Maria Andrea Reyes Reyes ¹, Diego Mauricio Quintero Santander ¹, Hernán Alfonso Gárnica Villamizar ¹, Jenny Andrea Oviedo Villamizar ¹, Edinson Andrés Puentes Cala ¹, Juan Sebastián Rivadeneira Pisciotti ², Javier Andrés Ceballos Ballesteros ², Jorge Hernando Panqueva Álvarez ¹ and Genis Andrés Castillo ¹

¹ 

Corrosión, Corporación para la Investigación de la Corrosión (CIC), Piedecuesta, 681011, Colombia

² 

Oleoducto de los Llanos Orientales S.A., Bogotá, Cundinamarca, Colombia

Microbiologically influenced corrosion (MIC) is critical in oil transportation systems, where biofilm formation accelerates metal deterioration, often leading to structural failures and economic losses. Several microbial groups contribute to MIC by interacting with the metal surface or by producing corrosive metabolites that facilitate localized metal loss. In this study, the microbial communities of pigging scrapings and water produced from crude oil and naphtha storage tanks in several oilfields in Colombia were characterized using next-generation sequencing technologies. Additionally, laboratory simulations evaluated MIC and biofilm formation under dynamic and static conditions using native microbial strains. Carbon steel coupons (AISI/SAE 1018) were installed in custom-designed bioreactors, a side-stream system, and exposure setups developed by the Corporación para la Investigación de la Corrosión (CIC). Exposure times ranged from 6 h to 120 days. Sessile bacterial counts were performed with liquid culture media, complemented by microscopy (SEM) for biofilm characterization and pitting depth determination. Biofilm formation was detected within 12 h, while sessile SRB colonization occurred at 6 h. After 90 days, the localized MIC pitting reached 35.5 µm, with a maximum corrosion rate of 5.5 mpy, classified as moderate according to the standard AMPP SP 0775-2023 [6]. These findings highlight rapid biofilm development and its correlation with MIC severity under both dynamic and static conditions. The present analysis confirms that the microbial composition associated with production has significant corrosive potential. The presence of these microorganisms and the pitting depths observed indicate a clear MIC threat in such systems. Implementing routine microbiological monitoring, optimizing maintenance schedules, and strengthening internal pipeline cleaning procedures are recommended to the reduce threat of MIC. In the case that MIC materializes in field-installed biocoupons and coupons, biocide treatments should be considered to prevent further structural degradation of oil transportation and storage systems.

7.5. Optimization of Zn-Ni Alloy Coating to Enhance Corrosion Resistance of Carbon Steel

• Kamelia Blyid ¹, Rida allah Belakhmima ² and Mohamed Ebn Touhami ¹

¹ 

Laboratory of Advanced Materials and Process Engineering, Department of Chemistry, Faculty of Sciences, Ibn Tofaïl University, Kenitra, Morocco

² 

Laboratory of Advanced Materials and Process Engineering, National Higher school of Chemistry, Ibn Tofaïl University, Kenitra, Morocco

Zn-Ni alloys have gained considerable attention due to their superior ability to resist corrosion. Zn-Ni electroplating can be improved by optimizing the nickel composition in Zn-Ni alloys, which provides better protection compared to Zinc deposited alone; it can also be improved by incorporating additives into the plating bath. The aim of our research was to optimize our electroplating bath by adding an eco-friendly additive to enhance the characteristics of the deposits obtained, particularly their morphology after electrodeposition, and their resistance against corrosion, using different concentrations of this additive (0 g/L, 0.25 g/L, 0.5 g/L, 1 g/L and 2 g/L). Several deposits were made for this purpose and their properties were investigated. We used scanning electron microscopy (SEM) to examine the deposits’ surface morphology, while energy-dispersive spectroscopy (EDS) was used to assess the chemical composition of the deposits. Electrochemical methods, polarization measurement (PDP) and electrochemical impedance spectroscopy (EIS), were used to investigate the corrosion resistance of every deposition in an ASTM D1384-87 [7] medium. The results show that the incorporation of the eco-friendly additive into the electroplating bath significantly improves both the morphology and corrosion resistance of Zn-Ni coatings. Compared to all the deposits produced in this study, the optimum concentration is 1 g/L of the additive, which produced the most corrosion-resistant Zn-Ni alloy deposit.

7.6. Synergistic Applications of Polypyrrole Coatings in Aluminum Food Cans: From Corrosion Protection to VOC Sensing

• Abdelqader El Guerraf ¹, Othmane Bannour ¹, Sana Ben Jadi ², Mohammed Bazzaoui ³ and El Arbi Bazzaoui ⁴

¹ 

Laboratory of Applied Chemistry and Environment, Faculty of Sciences and Technologies, Hassan First University, Settat 26002, Morocco

² 

Faculty of Sciences, Ibn Tofail University, Kenitra, Morocco

³ 

Materials and Environmental Laboratory, Faculty of Sciences, Ibn Zohr University, Agadir, Morocco

⁴ 

Laboratory of Applied Chemistry and Environment, Faculty of Sciences, Mohammed First University, Oujda 60000, Morocco

The increasing demand for advanced food packaging technologies has prompted the exploration of functional coatings that can extend the shelf life of food products while maintaining safety and quality. In this study, polypyrrole coatings were synthesized on aluminum can metals using various electroanalytical techniques across different electrolytic media, namely oxalic acid, sodium salicylate, and acetonitrile. The resulting films were subjected to extensive characterization through spectroscopic and microscopic techniques to assess their structural and compositional properties. The primary objective of this work was to evaluate the effectiveness of these polypyrrole (PPy) coatings in providing corrosion protection to aluminum cans, a critical factor for maintaining the integrity of food containers. Additionally, the films’ ability to detect volatile organic compounds (VOCs) was investigated, aiming to incorporate sensory functionalities into the packaging system. The results demonstrated that the polypyrrole coatings significantly enhanced the corrosion resistance of aluminum in various aggressive environmental conditions. Moreover, the films exhibited promising sensitivity to VOCs, paving the way for the development of intelligent packaging systems capable of the real-time monitoring of food freshness. This research underscores the potential of polypyrrole-based coatings as multifunctional materials for smart food packaging applications, combining protective and sensory capabilities to improve food safety and quality.

7.7. The Effect of Biocidal Treatments on Native Thiosulfate-Reducing Bacteria That Contibuteto Biocorrosion in the Oil and Gas Sectors

• Beatriz Elena Blandón Rojas ^1,2, Nicole Dayana Martínez Reyes ^1,3, Claudia Cecilia Barrios Barajas ⁴, Giovanni Juzga León ⁵, Genis Andrés Castillo Villamizar ⁶, Edinson Andrés Puentes Cala ⁶, Diego Mauricio Quintero Santander ⁶, Jorge Hernando Panqueva Álvarez ⁶ and Maria Andrea Reyes Reyes ^1,6

¹ 

Escuela de Microbiología, Universidad Industrial de Santander (UIS), Bucaramanga, 680002, Colombia

² 

Plagas y enfermedades área de fitopatología, Corporación Centro de Investigación en Palma de Aceite (CENIPALMA), Bogotá DC, 111121, Colombia

³ 

Apoyo diagnóstico, Hospital Regional José David Padilla Villafañe, Aguachica, 205010, Colombia

⁴ 

Integridad Mecánica y Corrosión, SierraCol Energy, Bogotá, 110808, Colombia

⁵ 

Integridad, Corporación para la Investigación de la Corrosión (CIC), Piedecuesta, 681011, Colombia

⁶ 

Corrosión, Corporación para la Investigación de la Corrosión (CIC), Piedecuesta, 681011, Colombia

Microbiologically influenced corrosion (MIC) is a phenomenon that contributes to the deterioration of metallic materials in industrial environments. This process has a significant impact on the infrastructure of oilfields, primarily affecting pipelines, storage tanks, and water distribution systems. The main bacterial groups associated with biocorrosion can be classified based on the metabolic pathways they employ. These include sulfate-reducing bacteria (SRB), acid-producing bacteria (APB), and thiosulfate-reducing bacteria (TRB), among others, which colonize and degrade metal surfaces through various metabolic mechanisms. This study aimed to evaluate the efficacy of different biocidal compounds in controlling TRB under laboratory conditions. The modified Time Kill Test (TKT) technique was employed using special BioCIC liquid culture media from the Corporación para la Investigación de la Corrosión (CIC). Seven biocide treatments were tested, including formulations based on tetrakis (hydroxymethyl) phosphonium sulfate (THPS), quaternary ammonium, and glutaraldehyde, among others. Bacterial incubation was conducted at 70 °C for 28 days to simulate field conditions. To identify microorganisms associated with biocorrosion in the production water at a Colombian oilfield, total genomic DNA was extracted from the samples and sequenced using the Oxford Nanopore Technology. Among the tested treatments, the M1 formulation (quaternary ammonium 10–30%, THPS 10–30%, and glutaraldehyde 10–30%) exhibited the highest antimicrobial efficacy, significantly reducing bacterial growth compared to the other biocides. The molecular identification of microbial communities in production water samples from seven different field locations revealed Thermotoga and Thermovirga as the predominant genera. However, post-TKT cultures treated with M1 showed a shift in microbial composition, with Acetomicrobium emerging as the dominant genus. These findings highlight the importance of evaluating diverse biocidal formulations to optimize MIC control strategies. Additionally, characterizing microbial populations in production waters is crucial for developing targeted mitigation approaches tailored to the specific microbial consortia present in each field.

8. Session: Metallic Materials Processing

8.1. Effect of Synergistic Burnishing–Tumbling Treatment on Surface Roughness, Microstructure, Hardness and Mechanical Strength of AISI 304 Alloys

• Zhe Xing Lee ¹, Ankit Shrivastava ², Mohammad Uddin ¹ and Colin Hall ²

¹ 

UniSA STEM, University of South Australia, Australia

² 

Future Industries Institute, University of South Australia, Australia

Any metal component failures (e.g., corrosion, fatigue) start from surface/subsurface defects (e.g., surface cracks, troughs, and pores). It is thus crucial to strengthen surface integrity by altering surface/subsurface properties in ways which provide protection from premature failure. To address this, in this paper, we presented a synergistic plasticity burnishing plus tumbling treatment to enhance the surface integrity and mechanical properties of cold-rolled AISI 304 steel alloys. A total of 304 steel specimens were ball-burnished, followed by a rotary tumbling process. The treated specimens were characterised in terms of surface roughness, 2D/3D topography hardness, and microstructures using laser confocal microscopy, SEM, a micro-hardness tester and EBSD analysis, respectively. Tensile tests were performed in accordance with ASTM standards to evaluate the Young’s modulus, yield strength, UTS and elongation. To evaluate the efficacy of the proposed synergistic approach, the results were compared and analysed across four types of specimens referred to as (1) “Untreated (as rolled)”, (2) “Burnished”, (3) “Tumbled” and (4) “Burnished+Tumbled”. The results showed that the ball burnishing resulted in grain modification and dislocation within the microstructure, improving the hardness and surface finish. But when the tumbling was applied to the burnished surface, the process augmented further hardness, grain modification, and yield strength, while there was a negligible impact on the fracture strength and elongation. These improved surface integrity properties are expected to enhance corrosion and fatigue life. The findings indicate that the combined burnishing–tumbling approach can extend the operational life of components subject to extreme loading conditions, thus saving huge costs by minimising premature failure.

8.2. Laser Marking of Stainless Steel and Aluminum

• Fábio A.O. Fernandes, Paulo J.A. Rosa and António B. Pereira
• TEMA—Centre for Mechanical Technology and Automation, Department of Mechanical Engineering, University of Aveiro, Portugal

The marking of components using laser technology is a permanent process that utilizes a beam to create a mark, or even engrave, on the surface of a component. Based on the potential for a high marking quality, this process is increasingly employed across various industries (semiconductors, electronics, medical, automotive, aerospace, etc.) for engraving serial numbers, logos, barcodes, QR codes, and more. Several laser processing parameters influence the marking quality as well as penetration. Depending on the component and material involved, these parameters must be adjusted to determine the optimal settings for each component/material. This study investigates the influence of laser beam parameters on marking quality to achieve the best set of laser marking conditions for different metals. A 30 W fiber laser was utilized, and the parametric study focused on power, frequency, marking speed, and the number of passes. The materials studied included aluminum alloy AW-6082-T6 and stainless steel 304 2B. The results demonstrate that the markings varied in color and quality, and it was possible to identify the optimal parameter sets for each material to ensure the best marking quality, even at high marking speeds. Overall, the marking strategy also influenced the marking quality, including the presence or absence of contours and the fill method used. This investigation also identified the degradation mechanisms associated with each material and how to mitigate undesirable effects, ensuring that the markings comply with industrial standards.

8.3. Exploring the Impact of MIG Brazing Techniques on Stability, Bead Morphology, and Joint Performance

• Jaivindra Singh ¹, João Pedro Oliveira ¹ and Kanwer Singh Arora ²

¹ 

CENIMAT/I3N, Department of Materials Science, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal

² 

Research & Development, Tata Steel Limited, Jamshedpur 831001, Jharkhand, India

This study explores the influence of various Metal Inert Gas (MIG) brazing modes on critical factors such as the process stability, bead morphology, microstructure and mechanical performance of brazed lap joints of dual-phase (DP600) steel. Through systematic analysis of voltage/current signals and deposition characteristics, this research reveals how variations in heat input impact material flow and wettability during the brazing process. A higher heat input has been found to enhance wettability and improve joint strength, yet it can lead to a reduction in the cross-sectional area, ultimately affecting resistance to failure. Conversely, lower heat inputs contribute to more stable deposition, which enhances resistance to failure and defects, but too low wettability can also cause premature failure of the joints. Additionally, this study identifies key process behaviours, including the tendency for increased instability at higher wire feed rates and the significant role of bead morphology in determining mechanical performance. By elucidating these process–property relationships, this research provides a valuable framework for selecting appropriate MIG brazing parameters tailored to specific applications. The findings significantly contribute to the development of process control strategies aimed at enhancing joint reliability, offering critical insights for industries focused on optimizing brazing techniques to achieve improved structural integrity and overall performance in their applications.

8.4. The Directional Solidification of Al-Zn Alloys as a Function of the Level of Convective Heat Transfer

• Jesús Darío Tirado Montoya, Reynel Brito Beltrán, Claudia Marcela Méndez, Natalia Silvina Zadorozne and Alicia Esther Ares
• Instituto de Materiales de Misiones (Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Misiones)

In this study, an analysis of the directional solidification of Al-Zn alloys using a Brigdman-type rotary directional solidification device is presented. For this purpose, the device can be rotated at three tilt angles (0°, 90°, and 180°). Directional solidification tests were performed with Al and Zn (commercial grade) and with Al-5%Zn and Al-10%Zn alloys (weight percent). The aim is to analyze how the furnace inclination (which generates different levels of convective heat transfer in the solidifying specimen) and the alloy composition influence the cooling rate of the metallic solid, the thermal gradients, and the size of the macrostructure and microstructure present. It has been observed that by varying the furnace inclination angles, for the same composition, the cooling rate tends to decrease; it is also important to highlight that the minimum temperature gradients coincide with the position of the CET. For commercial purity Al, average cooling rates of 2.21 °C/s at 90°, 2.05 °C/s at 45°, and 1.98 °C/s at 0° were obtained for each of the tests. For the Al-10wt. %Zn alloy, average cooling rates of 2.43 °C/s at 90°, 2.14 °C/s at 45°, and 1.99 °C/s at 0° are obtained, with a clear decrease in the cooling rate as the furnace tilt angle is varied. Similarly, when the CET occurs, the critical gradient value is −0.5 °C/cm for Al, 0.1 °C/cm for Zn, 1.4 °C/cm for Al-5wt. %Zn, and −1.2 °C/cm for Al-10wt. %Zn. On the other hand, when analyzing the behavior of Zn, it can be highlighted that the cooling rate values decrease significantly when compared with Al (both commercial grades) and with the Al-5wt. %Zn and Al-10wt. %Zn alloys. These data indicate that the alloy composition and the inclination of the solidification device influence the cooling rate and the thermal gradients.

8.5. The Potential Property-Tailoring Effects of Cryogenic Treatment on Pure Zinc

• Michael Johanes and Manoj Gupta
• Department of Mechanical Engineering, National University of Singapore

As of late, there has been increasing scope and demand for implants in the biomedical sector, notably in the field of orthopaedics. Within this field, zinc (Zn) is a promising base metal for such implants due to its combination of biocompatibility, mechanical properties, and corrosion response.

For the first time, pure Zn was successfully synthesized using the Disintegrated Melt Deposition (DMD) method and subjected to systematic cryogenic treatment (CT) study, with exposure to varying subzero temperatures (−20 °C, −50 °C, −80 °C, and −196 °C) for a duration of 24 h. Densification occurred for all materials (with a 35.9% porosity reduction after exposure to −50 °C being the most significant). Microstructurally, CT induced significant grain growth across all exposure temperatures, with − 80 °C conferring the largest grain size (224% increase over as-extruded equivalent). The compression response was also improved slightly after exposure to −50 °C, with improvements of 2.7%, 2.3%, and 1.0% to compressive yield strength, ultimate compressive strength, and work of fracture, respectively. Exposure to −196 °C also notably lowered corrosion rates (32.4% reduction compared to as-extruded equivalent).

These findings highlight the ability of CT to not just alter but tailor the individual properties of Zn-based materials, useful in specific applications. Furthermore, this also opens up a new research area for this Hexagonal Closed Pack (HCP) metal and its derivatives.

9. Session: Metallic Materials for Biomedical Applications

9.1. A Review on Perovskite Magnetic Nanoparticles (MNPs) Used in Magnetic Hyperthermia (HT)

• Mina Ahmadi ¹, Reza Ghomashchi ¹ and Daryoosh Vasjhaee ^2,3

¹ 

School of Electrical and Mechanical Engineering Faculty of Science, Engineering and Technology (SET) The University of Adelaide, Adelaide, SA 5005, Australia

² 

Department of Electrical and Computer Engineering, North Carolina State University, Raleigh, USA

³ 

Department of Materials Science and Engineering, North Carolina State University, Raleigh, USA

Magnetic hyperthermia (MHT) has emerged as an innovative cancer treatment modality that involves the generation of heat by exposing magnetic nanoparticles (MNPs) to an alternating magnetic field (AMF). This approach has attracted considerable attention due to its ability to locally elevate the temperature of tumor tissues in a non-invasive manner. MHT can be used either as a standalone treatment or in combination with other therapeutic strategies, such as surgery, chemotherapy, or radiotherapy, enhancing the overall therapeutic outcome. Among the various magnetic materials available for hyperthermia applications, perovskites stand out due to their unique crystalline structure and versatile electronic and magnetic properties. These characteristics make perovskites promising candidates for developing highly efficient MNPs that can be fine-tuned to optimize heat generation under an AMF.

This review focuses on the magnetic properties of perovskite-based nanoparticles and their potential for use in MHT. The article discusses several perovskites that have been explored for hyperthermic applications, examining their structural, magnetic, and thermal properties. Additionally, the synthesis methods employed for fabricating perovskite-based MNPs are thoroughly reviewed. Despite the promising potential, challenges remain in harnessing the full capability of perovskites in MHT, including issues related to stability, biocompatibility, and scalability. These limitations are also addressed in this review, and future directions are proposed, ensuring the widespread adoption of perovskites as efficient and reliable MNPs for magnetic hyperthermia in clinical settings.

9.2. Creation of Thin TiNi Wires with Stabilized Martensite Phase

• Nadezhda Artyukhova and Sergey Anikeev
• The Laboratory of Medical Materials Science, Tomsk State University, Russia

TiNi-based alloys have a unique set of functional and structural properties, which allows them to be used as materials for creating implants. Thin TiNi threads were obtained by drawing with intermediate chemical and mechanical treatments. Thinning the threads to 40–60 μm made it possible to manufacture textile implants for use in soft tissues of the human body. However, the Young’s modulus (E) of metallic TiNi-based materials can exceed that of soft connective tissues. Cryogenic treatment can reduce the elastic modulus by stabilizing the martensite phase and thereby reducing the rigidity of the material. This approach is novel and helps solve a fundamental problem in medical materials science.

Thin TiNi wires were obtained through the traditional technique and cryogen treatment. X-ray diffractometry, scanning electron microscopy, and energy dispersive spectroscopy allowed for determination of the structure and phase composition of thin wires with a composite structure based on TiNi(B2), TiNi₃, TiC, and TiO₂ phases. It was shown that the cryogenic treatment of thin TiNi wire resulted in the formation of two phases B2+B19 in the structure, which indicated martensite stabilization after cooling. The porosity of the obtained implants was 80 to 85%. SEM images of the structure of spherical implants after biointegration show the high integration tie between these implants and animal tissues. The high integration tie was observed between body tissues both inside and on the surface of the spherical implant.

This research was financially supported by Grant No. 24-29-00735 from the Russian Science Foundation.

9.3. Development of Mg-1Zn-1Ca-xZnO (x = 0 and 2 wt.%) Composite Using Disintegrated Melt Deposition Method for Biomedical Applications

• Hemant Kumar Pant ¹, Michael Johanes ², Amit Kumar Singh ¹, Jagadeesha T ¹ and Manoj Gupta ²

¹ 

Department of Mechanical Engineering, National Institute of Technology Calicut, Kozhikode, Kerala 673601, India

² 

Department of Mechanical Engineering, National University of Singapore, 9 Engineering, Drive 1, Singapore 117575, Singapore

Magnesium (Mg)-based biodegradable materials have become prominent for use in temporary implant applications. In the present work, the Mg-1Zn-1Ca-xZnO (x = 0 and 2 wt. %) alloy and composite were synthesized using a disintegrated melt deposition (DMD) technique followed by a hot extrusion process, and their microstructure, thermal, and mechanical properties were studied. The average grain size for the Mg-1Zn-1Ca alloy and the Mg-1Zn-1Ca-2ZnO composite obtained is 7.0 µm and 6.3 µm, respectively. The XRD analysis depicted that 10–11 pyramidal planes are dominant, and Mg₂Ca, Mg₂Ca and MgZn phases are formed in the Mg-1Zn-1Ca alloy and the Mg-1Zn-1Ca-2ZnO composite. The modulus of elasticity increased by 3.30% and the ignition temperature increased by 3.11% with the addition of 2 wt. % ZnO nanoparticles in the Mg-1Zn-1Ca alloy. The Vickers hardness value increased by 1.70% while the yield strength increased by 13.77% after the addition of ZnO nanoparticles (150.3 MPa and 171.0 MPa, respectively, for the monolithic Mg-1Zn-1Ca alloy and Mg-1Zn-1Ca-2ZnO composite materials, both of which exceed the yield strength of natural bone at 60–90 MPa). The results demonstrate the efficacy of ZnO nanoparticles for use in biomedical applications with good mechanical properties.

9.4. Enhanced Corrosion Resistance of Ti-6Al-4V Alloys via SLA-Treated Alginate-Based Hydrogels Incorporating CuO Nanoparticles

• Maosud Soroush Bathaei
• Department of Mining and Materials Engineering, McGill University, Montréal, QC, Canada

The biocompatibility and durability of titanium alloys, such as Ti-6Al-4V, are critical for their performance in biomedical applications. However, their susceptibility to corrosion in physiological environments remains a challenge. This study explores the synthesis and application of alginate-based hydrogels loaded with copper oxide nanoparticles (CuO NPs) as a protective coating on untreated and SLA-treated Ti-6Al-4V substrates. Alginate, a biopolymer with high hydrophilicity and biocompatibility, was selected for its potential to create a uniform hydrogel layer, while CuO NPs were incorporated for their known antimicrobial and corrosion-inhibitory properties. SLA treatment was employed to enhance surface roughness, promoting hydrogel adhesion.

The synthesized hydrogels were characterized using FTIR, confirming the successful incorporation of CuO NPs. Adhesion testing demonstrated superior hydrogel attachment to SLA-treated titanium surfaces due to increased surface roughness and energy. Corrosion resistance was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) in a simulated body fluid. The results revealed significant improvement in corrosion resistance for the hydrogel-coated samples compared to bare titanium, with the CuO NP-loaded hydrogels exhibiting the highest protection. This enhancement is attributed to the hydrogel’s barrier properties, which limit ion diffusion and reduce electrolyte access to the metal surface, counteracting the expected corrosion-promoting effect of a wet environment.

This research highlights the potential of SLA-treated, CuO NP-enriched alginate hydrogels to improve the longevity and performance of titanium implants by addressing both biocompatibility and corrosion resistance challenges.

9.5. Exploring the Potential of Nanostructured Metals in Biomedical Applications: A Review of Their Properties, Challenges, and Future Directions

• Natanael Codău
• “Ștefan cel Mare” University of Suceava, Faculty of Engineering and Computer Science, Specialization in Medical Equipment and Systems, Suceava, Romania

Nanostructured metals have gained considerable attention in biomedicine due to their superior properties, including enhanced wear resistance, improved biocompatibility, and the ability to interact favorably with human tissues. These materials are highly suitable for applications in the development of bioactive implants, prosthetics, medical devices, and other areas requiring high-performance materials. Compared to traditional metals, nanostructured materials exhibit significantly improved mechanical and chemical behaviors, enhancing their integration into the human body and reducing the risk of rejection or complications post-surgery.

A key advantage of nanostructured metals in biomedicine is their ability to improve biocompatibility by manipulating grain size and structural features at the nanometer scale. This modification enables better interaction with human tissues, minimizing risks such as inflammation or adverse reactions. Furthermore, nanostructuring significantly boosts the mechanical properties of metals, such as tensile strength and durability, making them ideal for prosthetics and implants that must endure substantial mechanical stress over extended periods.

Additionally, nanostructured metals can create bioactive surfaces that promote tissue regeneration or enable the targeted delivery of therapeutic substances. These capabilities make them particularly promising for controlled drug release applications, such as releasing anti-inflammatory or antibiotic agents directly at the site of injury or infection, thereby improving recovery times and preventing post-operative complications.

Nanostructured metals hold great promise for biomedical applications, but challenges remain in large-scale, cost-effective manufacturing and long-term stability in biological environments. Additionally, understanding their long-term effects on human health is an area that requires further research. This paper highlights the benefits, challenges, and limitations of nanostructured metals, while suggesting future research directions to improve manufacturing, performance, and integration in medical devices and implants.

9.6. Mechanical and Tribological Evaluation of a Biomedical High-Entropy Alloy Reinforced with TiC and TiB

• Danilo Cervantes Mauricio ¹, Vinícius Richieri Manso Gonçalves ², Jhuliene Elen Muro Torrento ³, Carlos Roberto Grandini ³ and Diego Rafael Nespeque Correa ¹

¹ 

São Paulo State University (UNESP), School of Sciences, Bauru, Laboratório de Anelasticidade e Biomateriais, 17033-360, Bauru, Brazil

² 

Federal University of São Carlos (UFSCar), Department of Materials Engineering, 3565-905, São Carlos, Brazil

³ 

São Paulo State University (UNESP), School of Sciences, Campus Bauru, Laboratory of Anelasticity and Biomaterials, 17.033-360 Bauru, SP, Brazil

High-entropy alloys (HEAs) are emerging materials that have recently been considered for biomedical applications. However, further adjustments in their properties are still needed to potentialize this application. Thus, research on novel processing routes is interesting for producing such advanced biomedical HEAs. In this study, we synthesized a novel metal–matrix composite (MMC) using an HEA as the matrix, which was reinforced with TiB and TiC particles. The sample was produced by argon arc melting a TiNbZrTaMo ingot with B₄C powder to induce in situ reactions. The resulting sample underwent extensive evaluations, including physical, chemical, structural, microstructural, mechanical, tribological, and biological assessments, and was compared to the unreinforced HEA sample. X-ray diffraction confirmed the in situ reactions, revealing a dual-phase (BCC + HCP) matrix with TiC and TiB peaks. Scanning and transmission electron microscopy showed that the BCC phase was enriched with refractory metals (Ta, Mo, and Nb), while the HCP and carbide precipitate phases were enriched with Ti and Zr. The results demonstrated strong interfacial bonding between the TiC precipitate and the matrix. Mechanical property analysis indicated that the precipitates retained a combination of high microhardness and a relatively low elastic modulus. Despite this, the precipitates enhanced wear resistance without offering any benefits in terms of corrosion resistance. Cytotoxicity tests showed that the precipitates positively influenced cell viability and adhesion. These findings highlight the potential for developing novel biomedical materials by combining HEA and MMC concepts. (Financial support: CNPq and FAPESP grant #2024/03148-3).

9.7. Study of Corrosion Behavior of Biocompatible Porous Monolithic Material Based on Titanium Nickelide

• Elena Aldisovna Bolshevich and Sergey Gennadievich Anikeev
• National Research Tomsk State University, Russian Federation, Russia

Introduction: Corrosion resistance is one of the most important requirements for medical devices, as it determines the service life of the material. The aim of this work is to study the corrosion resistance of new biocompatible porous monolithic materials based on titanium nickelide (TiNi), with a different ratio of the reaction additive in the powder system (TiNi:(Ti-Ni)).

Materials and methods: Porous monolithic samples consisting of a monolithic TiNi plate with a porous powder surface were used as the studied material. The surface was powder mixture A–B, where mixture A was (5%Ti+0.5%Ni+TiNi), with exothermic additive B (Ti+Ni) in various ratios: TiNi (1-1), TiNi (1-0.75), TiNi (1-0.5). Sintering was carried out at a temperature of 1100 °C and was held for 15 min in an electric vacuum furnace. To homogenize the surface, the studied samples were subjected to electron beam treatment. The determination of corrosion resistance was carried out using voltammetry, with a linear potential sweep in a physiological solution.

Results: According to the data obtained from the electrochemical studies, it was established that the rate of corrosion is influenced by the amount of an exothermic additive. The lowest corrosion rate was observed in the TiNi with the highest content: the value of the corrosion rate of the TiNi sample (1-1) was about 2.5 times less than in TiNi (1-0.5). Microscopic analysis showed the presence of local fractures on the surface of the material after electrochemical tests, including cracks and pitting. The porous areas of the material were mainly corroded; therefore, the corrosion rate increases with a decrease in the amount of the exothermic additive.

Conclusions: As a result of the work performed, it is shown that an increase in the proportion of exothermic additives leads to an increase in the corrosion resistance parameters of porous monolithic materials based on TiNi.

9.8. Surface Roughness Optimization of CP Titanium for Improved Osseointegration in Dental Implants

• Amantle Balang ¹, Gordon Blunn ², Nigel Smith ³, Pavel Shashkov ³, Marta Roldo ², Katerina Karali ¹ and Roxane Bonithon ¹

¹ 

University of Portsmouth, School of Electrical and Mechanical Engineering, UK

² 

University of Portsmouth, School of Medicine, Pharmacy and Biomedical Sciences, UK

³ 

BioCera Medical Limited, UK

Introduction: Surface topography plays a critical role in optimizing titanium implants for enhanced osseointegration—a phenomenon first described by Prof. Brånemark in 1952. His pioneering discovery led to dental implants with a surface roughness (Ra) of approximately 0.15 µm achieved through electropolishing. Advances in bone fixation have since introduced various surface treatments to improve implant roughness favouring cell adhesion. This study investigates the roughness of commercially pure (CP) titanium treated with electrochemical oxidation coatings to assess their suitability for dental applications.

Methods: CP titanium specimens (n = 6) underwent surface coating via a proprietary electrochemical oxidation (ECO) of Biocera Medical (WO 2020/049299) in phosphate–zirconate electrolyte with four different concentrations of zinc (Zn) additive: Type 1 (Zr-P), Type 2 (Zr-P-Zn (L)), Type 3 (Zr-P-Zn (M)), and Type 4 (Zr-P-Zn (H)). Surface roughness of applied zirconia–Titania ceramic enriched with P and Zn was measured using a Keyence digital microscope (4 readings per sample) and three-dimensional parameters (Sa, Sq, Sz) following ISO 25178.

Results: Coated titanium surfaces demonstrated increased roughness compared to uncoated titanium (Sa = 0.45 ± 0.07 µm). Coating Type 1 had a minimal impact on roughness (Sa = 0.49 ± 0.09 µm), while Types 2, 3, and 4 increased the mean Sa values to 0.63 ± 0.07 µm, 0.66 ± 0.05 µm, and 0.72 ± 0.10 µm, respectively. The roughness is not homogeneous, following lines for uncoated Ti while it is more spotted for coated samples, as observed on 3D Sa maps.

Conclusions: Electrochemical oxidation coatings enriched with Zn increased the roughness of CP Ti surfaces. The higher roughness of Types 2–4 may enhance osseointegration by promoting cell attachment and therefore would improve titanium’s surface properties for dental implants. Further research will expand the analysis of coating properties with SEM/EDS imaging, nano-indentation, and biological performance.