Journal of Manufacturing and Materials Processing

18 pages, 2112 KiB

Open AccessArticle

Additive vs. Subtractive Manufacturing: A Comparative Life Cycle and Cost Analyses of Steel Mill Spare Parts

by Luis Segovia-Guerrero, Nuria Baladés, Juan J. Gallardo-Galán, Antonio J. Gil-Mena and David L. Sales

J. Manuf. Mater. Process. 2025, 9(4), 138; https://doi.org/10.3390/jmmp9040138 - 19 Apr 2025

Viewed by 193

Abstract

In the context of growing environmental concerns and the demand for more sustainable manufacturing practices, this study evaluates the environmental and economic performance of two production routes for a stainless steel support block used in steel mills. A comparative Life Cycle Assessment (LCA) [...] Read more.

In the context of growing environmental concerns and the demand for more sustainable manufacturing practices, this study evaluates the environmental and economic performance of two production routes for a stainless steel support block used in steel mills. A comparative Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) were conducted to assess a conventional subtractive manufacturing process based on Computer Numerical Control (CNC) machining versus a hybrid approach that combines Plasma Arc-Wire Arc Additive Manufacturing (PA-WAAM) with CNC finishing. The LCA was carried out using ReCiPe 2016 Midpoint and Endpoint methodologies in SimaPro, while the LCC employed a cradle-to-gate cost model. Results showed that the hybrid WAAM-CNC route reduced average environmental impacts by 49% across 18 categories and decreased steel consumption by approximately 70% due to near-net-shape fabrication. Although the hybrid method incurred an approximate 3.5 times increase in unit production cost, this was primarily attributed to equipment investment. In contrast, operational costs such as labor, materials, and consumables were significantly lower—by 66%, 28%, and 45%, respectively. These findings support the hybrid approach as a more sustainable manufacturing alternative with the potential for long-term cost optimization as additive technologies mature. Full article

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25 pages, 5232 KiB

Open AccessArticle

An Advanced Compression Molding Simulation and Validation of a Thick-Walled Carbon Fiber Sheet Molding Compound Brake Caliper

by Andreas Kapshammer, Severin Huemer-Kals, Kepa Zulueta, Peter Fischer and Zoltan Major

J. Manuf. Mater. Process. 2025, 9(4), 137; https://doi.org/10.3390/jmmp9040137 - 19 Apr 2025

Viewed by 121

Abstract

This study introduces a methodology for characterizing and modeling the viscosity and specific volume–pressure–temperature (pvT) behavior of sheet molding compound (SMC) materials, based on the use of specialized testing equipment. Conventional rheometers are inadequate for such materials due to the presence of long [...] Read more.

This study introduces a methodology for characterizing and modeling the viscosity and specific volume–pressure–temperature (pvT) behavior of sheet molding compound (SMC) materials, based on the use of specialized testing equipment. Conventional rheometers are inadequate for such materials due to the presence of long fibers, necessitating the use of specialized equipment like squeeze flow rheometers and pvT dilatometers. Our findings demonstrate that traditional oscillatoric rheometer measurements underestimate the viscosity of CF-SMCs, highlighting the need for advanced, albeit non-standardized, testing methods. Additionally, we found that standard Tait models failed to capture the temperature-dependent porosity of CF-SMCs at low pressures, whereas models based on thermodynamic state variables (TSVs) provided accurate predictions across a broader range of conditions. The study also addressed the complexities introduced by fiber–flow coupling and the fiber orientation in measuring the viscosity, revealing limitations in conventional modeling approaches. The numerical analysis showed that a power law-based anisotropic viscosity model (PL-IISO) combined with a TSV model offered the best predictive performance in finite volume flow simulations, especially for thick-walled regions. However, the current modeling approaches have limited predictive capabilities for the fiber orientation in thin-walled regions. This research underscores the challenges in accurately modeling CF-SMC materials in terms of the fiber orientation, whereas the compression forces needed from the pressing machine could be predicted accurately within an average error of 6.5% in the squeeze flow experiments. Full article

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12 pages, 4385 KiB

Open AccessArticle

Effects of Compaction Thickness on Density, Integrity, and Microstructure of Green Parts in Binder Jetting Additive Manufacturing of Silicon Carbide

by Mostafa Meraj Pasha, Md Shakil Arman, Zhijian Pei, Fahim Khan, Jackson Sanders and Stephen Kachur

J. Manuf. Mater. Process. 2025, 9(4), 136; https://doi.org/10.3390/jmmp9040136 - 19 Apr 2025

Viewed by 161

Abstract

Binder jetting additive manufacturing (BJAM) of silicon carbide (SiC) has been reported in the literature. In the reported studies, the effects of the compaction thickness on the properties of SiC green parts printed by BJAM have largely been unexamined. This study aims to [...] Read more.

Binder jetting additive manufacturing (BJAM) of silicon carbide (SiC) has been reported in the literature. In the reported studies, the effects of the compaction thickness on the properties of SiC green parts printed by BJAM have largely been unexamined. This study aims to fill this gap in the literature by investigating the effects of the compaction thickness on the density, integrity, and microstructure of SiC green parts printed by BJAM. In this study, experiments were conducted using four levels of compaction thickness at two levels of layer thickness. The results indicate that increasing the compaction thickness enhances the green part density, reaching 1.85 g/cm³ at a layer thickness of 45 µm and 1.87 g/cm³ at a layer thickness of 60 µm, respectively. However, a higher compaction thickness might also introduce defects in green parts, such as cracks. Scanning electron microscopy (SEM) analysis confirmed the improved particle packing and reduced porosity with the increased compaction thickness. These findings underscore a trade-off between density and defect formation, providing critical insights for optimizing BJAM process variables for fabricating SiC parts. Full article

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13 pages, 3162 KiB

Open AccessArticle

Effect of Varying Layer Thickness by Interlayer Machining on Microstructure and Mechanical Properties in Wire Arc Additive Manufacturing

by G. Ganesan, Neel Kamal Gupta, S. Siddhartha, Shahu R. Karade, Henning Zeidler, K. Narasimhan and K. P. Karunakaran

J. Manuf. Mater. Process. 2025, 9(4), 135; https://doi.org/10.3390/jmmp9040135 - 18 Apr 2025

Viewed by 168

Abstract

This study investigates the influence of varying layer thickness through interlayer machining in Wire Arc Additive Manufacturing (WAAM) and its impact on microstructural evolution, mechanical properties, and residual stress distribution. It compares four types of WAAM samples: As-built with uneven layer thickness without [...] Read more.

This study investigates the influence of varying layer thickness through interlayer machining in Wire Arc Additive Manufacturing (WAAM) and its impact on microstructural evolution, mechanical properties, and residual stress distribution. It compares four types of WAAM samples: As-built with uneven layer thickness without interlayer machining and uniform layer thicknesses of 2 mm, 1.5 mm, and 1 mm achieved through interlayer machining. As-built components exhibited coarse columnar grains and uneven deposition, adversely affecting hardness and strength. Interlayer machining at reduced layer thickness refined grains, restricted growth, and induced plastic deformation, leading to enhanced mechanical properties. Grain refinement achieved reductions of 62.7% (top), 77.6% (middle), and 64.3% (bottom), significantly improving microstructural uniformity. Microhardness increased from 150 to 180 HV (as-built) to 210 to 230 HV (machined to maintain 1 mm layer thickness), marking a 40–43% improvement. Tensile strength was enhanced, with UTS increasing from 494.72 MPa to 582.11 MPa (17.6%) and YS from 371 MPa to 471 MPa (26.9%), although elongation decreased from 59% to 46% (22% reduction). Residual stress was reduced by 55–60%, improving structural integrity. These findings highlight interlayer machining as a key strategy for optimizing WAAM-fabricated components while balancing mechanical performance and manufacturing efficiency. Full article

(This article belongs to the Special Issue Design, Processes and Materials for Additive Manufacturing: 2nd Edition)

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21 pages, 5818 KiB

Open AccessArticle

Influence of Infill Geometry and Density on the Mechanical Properties of 3D-Printed Polylactic Acid Structure

by Jozef Jaroslav Fekiač, Lucia Kakošová, Michal Krbata, Marcel Kohutiar, Maroš Eckert, Zbynek Studeny and Andrej Dubec

J. Manuf. Mater. Process. 2025, 9(4), 134; https://doi.org/10.3390/jmmp9040134 - 18 Apr 2025

Viewed by 150

Abstract

Additive manufacturing of polymer composites, also known as 3D printing, is one of the progressive technologies in material engineering. It enables the production of parts with complex geometries while optimizing material efficiency. Polylactide (PLA) is a widely used material in additive manufacturing due [...] Read more.

Additive manufacturing of polymer composites, also known as 3D printing, is one of the progressive technologies in material engineering. It enables the production of parts with complex geometries while optimizing material efficiency. Polylactide (PLA) is a widely used material in additive manufacturing due to its biodegradability and suitable mechanical properties. However, its brittleness and limited thermal stability require further modifications, such as modifying the filler structure or adding reinforcing materials. This paper focuses on analyzing the influence of different filler geometries and densities on the mechanical properties of PLA parts manufactured by the fused filament deposition (FFF) method. Three basic filler structures—cubic, gyroid and rectilinear—were investigated at different density levels from 20%, 40%, 60% and 80%. Experimental tests were performed according to ASTM D638 to determine the strength characteristics of the material. In addition to mechanical tests, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TG) were performed to better understand the influence of the filling geometry on the thermal stability and viscoelastic behavior of the material. Experimental tests according to ASTM D638 showed that higher filling density improves mechanical properties. At 80% filling, the tensile strength reached 21.06 MPa (cubic), 20.53 MPa (gyroid) and 20.84 MPa (linear). The elastic modulus was highest with cubic filling (1414.19 MPa). The yield strength reached 15.59 MPa (cubic), 15.52 MPa (gyroid) and 14.30 MPa (linear). Full article

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39 pages, 8029 KiB

Open AccessReview

Recent Advances in In Situ 3D Surface Topographical Monitoring for Additive Manufacturing Processes

by Vignesh Suresh, Badrinath Balasubramaniam, Li-Hsin Yeh and Beiwen Li

J. Manuf. Mater. Process. 2025, 9(4), 133; https://doi.org/10.3390/jmmp9040133 - 18 Apr 2025

Viewed by 213

Abstract

Additive manufacturing (AM) has revolutionized production across industries, yet persistent challenges in defect detection and process reliability necessitate advanced in situ monitoring solutions. While non-destructive evaluation (NDE) techniques such as X-ray computed tomography, thermography, and ultrasonic testing have been widely adopted, the critical [...] Read more.

Additive manufacturing (AM) has revolutionized production across industries, yet persistent challenges in defect detection and process reliability necessitate advanced in situ monitoring solutions. While non-destructive evaluation (NDE) techniques such as X-ray computed tomography, thermography, and ultrasonic testing have been widely adopted, the critical role of 3D surface topographic monitoring remains underutilized for real-time anomaly detection. This work comprehensively reviews the 3D surface monitoring of AM processes, such as Laser powder bed fusion, directed energy deposition, material extrusion, and material jetting, highlighting the current state and challenges. Furthermore, the article discusses the state-of-the-art advancements in closed-loop feedback control systems, sensor fusion, and machine learning algorithms to integrate 3D surface data with various process signatures to dynamically adjust laser parameters and scan strategies. Guidance has been provided on the best 3D monitoring technique for each of the AM processes. Motivated by manufacturing labor shortages, the high skill required to operate and troubleshoot some of these additive manufacturing techniques, and zero-defect manufacturing goals, this paper also explores the metamorphosis towards autonomous AM systems and adaptive process optimization and explores the role and importance of real-time 3D monitoring in that transition. Full article

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27 pages, 14022 KiB

Open AccessArticle

Personalizing Industrial Maintenance Operation Using the Model of Hierarchical Complexity

by Gonçalo Raposo, Nuno Araújo, Marco Parente, António M. Lopes, Adriano Santos, Filipe Pereira, Sofia Leite and António Ramos Silva

J. Manuf. Mater. Process. 2025, 9(4), 132; https://doi.org/10.3390/jmmp9040132 - 15 Apr 2025

Viewed by 252

Abstract

The rapid advancement of Industry 4.0 technologies has transformed industrial maintenance operations, introducing digital work instructions as a critical tool for improving efficiency and reducing errors. However, existing digitalization approaches often fail to account for variations in worker expertise, leading to cognitive overload, [...] Read more.

The rapid advancement of Industry 4.0 technologies has transformed industrial maintenance operations, introducing digital work instructions as a critical tool for improving efficiency and reducing errors. However, existing digitalization approaches often fail to account for variations in worker expertise, leading to cognitive overload, frustrations, and overall inefficiency. This study proposes a novel methodology for dynamically personalizing digital work instructions by structuring task instructions based on complexity levels and worker proficiency. Using the Model of Hierarchical Complexity (MHC) as a framework ensures that operators receive guidance tailored to their cognitive and skill capabilities. The methodology is implemented and evaluated in an industrial maintenance environment, where digital work instructions are adapted based on worker profiles. The results show significant improvements in maintenance operations, including a reduction in task completion time, a decrease in error rates, and enhanced worker engagement. Comparative analysis with conventional static instructions reveals that personalized digital work instructions contribute to a more effective knowledge transfer process, reducing cognitive strain and enhancing procedural adherence. Additionally, integrating predictive maintenance strategies with personalized work instructions could further enhance operational efficiency by enabling proactive decision-making. Addressing potential challenges, such as worker resistance to adaptive technologies and data privacy concerns, will be crucial for widespread implementation. In conclusion, leveraging the Model of Hierarchical Complexity to personalize digital work instructions represents a significant step toward optimizing industrial maintenance workflows. Tailoring instructional content to individual skill levels and cognitive abilities enhances workforce productivity, reduces errors, and contributes to the broader objectives of Industry 4.0. Full article

(This article belongs to the Special Issue Haptic-Robotic Systems in Industrial Design, Manufacturing, Assembly, Simulation, and Training)

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16 pages, 10278 KiB

Open AccessReview

Ag/Au Bimetallic Core–Shell Nanostructures: A Review of Synthesis and Applications

by Shuyue He, Ziyu Tang, Tianhang Huo, Di Wu and Jasper H. Tang

J. Manuf. Mater. Process. 2025, 9(4), 131; https://doi.org/10.3390/jmmp9040131 - 15 Apr 2025

Viewed by 245

Abstract

Silver/gold (Ag/Au) core–shell nanostructures exhibit tunable plasmonic properties and enhanced catalytic performance, enabling applications across sensing, biomedicine, and environmental remediation. This review presents representative synthetic strategies for fabricating Ag/Au bimetallic core–shell nanostructures with three distinct morphologies: nanospheres, nanocubes, and nanowires. For each architecture, [...] Read more.

Silver/gold (Ag/Au) core–shell nanostructures exhibit tunable plasmonic properties and enhanced catalytic performance, enabling applications across sensing, biomedicine, and environmental remediation. This review presents representative synthetic strategies for fabricating Ag/Au bimetallic core–shell nanostructures with three distinct morphologies: nanospheres, nanocubes, and nanowires. For each architecture, we cover the representative synthetic approaches, such as seed-mediated growth, one-pot synthesis, and evaporation deposition methods, along with their corresponding applications. This review provides discussions on the synthesis methods and applications through specific examples, offering researchers guidance for fabricating Ag/Au core–shell nanostructures with tailored morphologies while addressing major challenges in controlling bimetallic formation. Full article

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13 pages, 18986 KiB

Open AccessArticle

Thermal Modelling of Metals and Alloys Irradiated by Pulsed Electron Beam: Focus on Rough, Heterogeneous and Multilayered Materials

by Andrea Lucchini Huspek, Valentina Mataloni, Ali Mohtashamifar, Luca Paterlini and Massimiliano Bestetti

J. Manuf. Mater. Process. 2025, 9(4), 130; https://doi.org/10.3390/jmmp9040130 - 15 Apr 2025

Viewed by 211

Abstract

Low-Energy High-Current Electron Beam (LEHCEB) is an innovative vacuum technology employed for the surface modification of conductive materials. Surface treatments by means of LEHCEB allow the melting and rapid solidification of a thin layer (up to ~10 μm) of material. The short duration [...] Read more.

Low-Energy High-Current Electron Beam (LEHCEB) is an innovative vacuum technology employed for the surface modification of conductive materials. Surface treatments by means of LEHCEB allow the melting and rapid solidification of a thin layer (up to ~10 μm) of material. The short duration of each pulse (2.5 μs) allows for the generation of high thermal rates, up to 10⁹ K/s. Due to the peculiar features of LEHCEB source, in situ temperature monitoring inside the vacuum chamber is unfeasible, even with the most rapid IR pyrometers available on the market. Therefore, multiphysics simulations serve as a tool for predicting and assessing the thermal effects induced by electron beam irradiation. COMSOL Multiphysics was employed to study the thermal behaviour of metals and alloys at the sub-microsecond time scale by implementing both experimental power time profiles and semi-empirical electron penetration functions. Three case studies were considered: (a) 17-4 PH steel produced by Binder Jetting, (b) biphasic Al-Si13 alloy, and (c) Magnetron Sputtering Nb films on Ti substrate. The influence on the thermal effects of electron accelerating voltage and number of pulses was investigated, as well as the role of the physicochemical properties of the materials. Full article

(This article belongs to the Special Issue New Trends in Precision Machining Processes)

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38 pages, 4194 KiB

Open AccessReview

Recent Trends and Future Directions in 3D Printing of Biocompatible Polymers

by Maryam Aftab, Sania Ikram, Muneeb Ullah, Niyamat Khan, Muhammad Naeem, Muhammad Amir Khan, Rakhmonov Bakhrombek Bakhtiyor o’g’li, Kamalova Sayyorakhon Salokhiddin Qizi, Oribjonov Otabek Erkinjon Ugli, Bekkulova Mokhigul Abdurasulovna and Oribjonova Khadisakhon Abdumutallib Qizi

J. Manuf. Mater. Process. 2025, 9(4), 129; https://doi.org/10.3390/jmmp9040129 - 14 Apr 2025

Viewed by 532

Abstract

Three-dimensional (3D) bioprinting using biocompatible polymers has emerged as a revolutionary technique in tissue engineering and regenerative medicine. These biopolymers mimic the extracellular matrix (ECM) and enhance cellular behavior. The current review presents recent advancements in additive manufacturing processes including Stereolithography (SLA), Fused [...] Read more.

Three-dimensional (3D) bioprinting using biocompatible polymers has emerged as a revolutionary technique in tissue engineering and regenerative medicine. These biopolymers mimic the extracellular matrix (ECM) and enhance cellular behavior. The current review presents recent advancements in additive manufacturing processes including Stereolithography (SLA), Fused Filament Fabrication (FFF), Selective Laser Sintering (SLS), and inkjet printing. It also explores the fundamentals of 3D printing and the properties of biocompatible polymers for 3D bioprinting. By mixing biopolymers, enhancing rheological characteristics, and adding bioactive components, further advancements have been made for organ transplantation, drug development, and tissue engineering. As research progresses, the potential for 3D bioprinting to fundamentally transform the healthcare system is becoming obvious and clear. However, the therapeutic potential of printed structures is hindered by issues such as material anisotropy, poor mechanical properties, and the need for more biocompatible and biodegradable architectures. Future research should concentrate on optimizing the 3D bioprinting process using sophisticated computational techniques, systematically examining the characteristics of biopolymers, customizing bioinks for different cell types, and exploring sustainable materials. Full article

(This article belongs to the Special Issue Advances in 3D Printing Technologies: Materials, Processes, and Applications)

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15 pages, 8253 KiB

Open AccessArticle

An Investigation of the Fatigue Behavior and Dislocation Substructures of Friction-Stir-Welded SSM 6063 Aluminum Alloy

by Kittima Sillapasa, Konkrai Nakowong, Siriporn Khantongkum and Chaiyoot Meengam

J. Manuf. Mater. Process. 2025, 9(4), 128; https://doi.org/10.3390/jmmp9040128 - 14 Apr 2025

Viewed by 426

Abstract

In this study, we examine the evolution of dislocation substructures influenced by the fatigue behavior of SSM 6063 aluminum alloy processed through friction stir welding (FSW). The findings indicate that dislocation substructures have a significant impact on fatigue life. Cyclic loading induced recrystallization [...] Read more.

In this study, we examine the evolution of dislocation substructures influenced by the fatigue behavior of SSM 6063 aluminum alloy processed through friction stir welding (FSW). The findings indicate that dislocation substructures have a significant impact on fatigue life. Cyclic loading induced recrystallization in the stir zone (SZ), the advancing-side thermomechanically affected zone (AS-TMAZ), and the retreating-side thermomechanically affected zone (RS-TMAZ). The transformation of the α-primary aluminum matrix phase into an S/S’ structure and the precipitation of Al₅FeSi intermetallic compounds into the T-phase were observed. Furthermore, the precipitation of Si and Mg, the primary alloying elements, was observed in the Guinier–Preston (GP) zone within the SZ. Transmission electron microscopy (TEM) analysis revealed small rod-like particles in the T-phase, measuring approximately 10–20 nm in width and 20–30 nm in length in the SZ. In the AS-TMAZ, these rod-like structures ranged from 10 to 120 nm in width and 20 to 180 nm in length, whereas in the RS-TMAZ, they varied between 10 and 70 nm in width and from 20 to 110 nm in length. The dislocation substructures influenced the stress amplitude, which was 42.46 MPa in the base metal (BM) and 33.12 MPa in the FSW-processed SSM 6063 aluminum alloy after undergoing more than 2 × 10⁶ loading cycles. The endurance limit was 42.50 MPa for BM and 32.40 MPa for FSW. Fractographic analysis of the FSW samples revealed distinct laminar crack zones and shear fracture surface zones, differing from those of other regions. Both brittle and ductile fracture characteristics were identified. Full article

(This article belongs to the Special Issue Deformation and Mechanical Behavior of Metals and Alloys)

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15 pages, 4008 KiB

Open AccessArticle

Optimization of Process Parameters in Electropolishing of SS 316L Utilizing Taguchi Robust Design

by Muhammad Kemal Syahputra, Kartika Nur ‘Anisa’, Rizky Astari Rahmania, Farazila Yusof, Pradeep Dixit, Muslim Mahardika and Gunawan Setia Prihandana

J. Manuf. Mater. Process. 2025, 9(4), 127; https://doi.org/10.3390/jmmp9040127 - 11 Apr 2025

Viewed by 225

Abstract

In electropolishing, the material removal rate is frequently neglected, as this process is primarily focused on surface finish, and yet, it is crucial for manufacturing metallic sheets. Solutions are required to enhance the material removal rate while maintaining surface quality. This work introduces [...] Read more.

In electropolishing, the material removal rate is frequently neglected, as this process is primarily focused on surface finish, and yet, it is crucial for manufacturing metallic sheets. Solutions are required to enhance the material removal rate while maintaining surface quality. This work introduces an electropolishing technique that involves suspending ethanol in an electrolyte solution and employing a magnetic field during machining processes. The Taguchi approach is utilized to determine the ideal process parameters for enhancing the material removal rate of SS 316L electropolishing through a L9 orthogonal array. Pareto analysis of variance (ANOVA) is utilized to examine the four parameters of the machining process: applied voltage, ethanol concentration, machining gap variation, and the magnetic field of the electrolyte. The results demonstrate that the applied voltage, the incorporation of ethanol in electropolishing, and a reduced machining gap significantly increase the material removal rate; however, the introduction of a magnetic field did not notably increase the material removal rate. Full article

(This article belongs to the Topic Advanced Manufacturing and Surface Technology, 2nd Edition)

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26 pages, 7455 KiB

Open AccessArticle

Accuracy Optimization of Robotic Machining Using Grey-Box Modeling and Simulation Planning Assistance

by Minh Trinh, Michael Königs, Lukas Gründel, Marcel Beier, Oliver Petrovic and Christian Brecher

J. Manuf. Mater. Process. 2025, 9(4), 126; https://doi.org/10.3390/jmmp9040126 - 11 Apr 2025

Viewed by 274

Abstract

The aim of this paper is to develop an approach to increase the accuracy of industrial robots for machining processes. During machining tasks, process forces displace the end effector of the robot. A simulation of the various process influences is therefore necessary to [...] Read more.

The aim of this paper is to develop an approach to increase the accuracy of industrial robots for machining processes. During machining tasks, process forces displace the end effector of the robot. A simulation of the various process influences is therefore necessary to ensure stable machining during production planning in optimizing the process parameters. Realistic simulations require precise dynamics and stiffness models of the robot. Regarding the dynamics, the frictional component is highly complex and difficult to model. Therefore, this paper follows a grey-box approach to combine the advantages of the state-of-the-art Lund–Grenoble model (white-box) with those of a data-driven one (black-box) in the first part. The resulting grey-box LuGre model proves to be superior to the white- and black-box models. In the second part, a model-based simulation planning assistance tool is developed, which makes use of the grey-box LuGre model. The simulation assistance provides the manufacturing planner with process knowledge using the identified robot and cutting force models. Furthermore, it provides optimization methods such as a switching point analysis. Finally, the assistance tool gives predictions about the machining result and a process evaluation. The third part of the paper shows the evaluation of the simulation assistance on a real machining process and workpiece, showing an increase in accuracy using the tool. Full article

(This article belongs to the Special Issue Recent Progress in Robotic Machining)

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15 pages, 4776 KiB

Open AccessArticle

Stack and Structure: Ultrafast Lasers for Additive Manufacturing of Thin Polymer Films for Medical Applications

by Dominic Bartels, Yvonne Reg, Mahboobeh Borandegi, Maximilian Marschall, Alexander Sommereyns and Michael Schmidt

J. Manuf. Mater. Process. 2025, 9(4), 125; https://doi.org/10.3390/jmmp9040125 - 8 Apr 2025

Viewed by 307

Abstract

Overcoming the limitations of powder-based additive manufacturing processes is a crucial aspect for the manufacturing of patient-specific sophisticated implants with tailored properties. Within this work, a novel manufacturing process for the fabrication of polymer-based implants is proposed. This manufacturing process is inspired by [...] Read more.

Overcoming the limitations of powder-based additive manufacturing processes is a crucial aspect for the manufacturing of patient-specific sophisticated implants with tailored properties. Within this work, a novel manufacturing process for the fabrication of polymer-based implants is proposed. This manufacturing process is inspired by the laminated object manufacturing technology and is based on using thin films as raw material, which are processed using an ultrafast laser source. Utilizing thin films as a starting material helps to avoid powder contamination during additive manufacturing, thus supporting the generation of internal cavities that can be filled with secondary phases. Additionally, the use of medical materials mitigates the burden of a later certification of potential implants. Furthermore, the ultrafast laser supports the generation of highly resolved structures smaller than the average layer thickness (from 50 to 100 µm) through material ablation. These structures can be helpful to obtain progressive part properties or a targeted stress flow, as well as a specified release of secondary phases (e.g., hydrogels) upon load. Within this work, first investigations on the joining, cutting, and structuring of thin polymer films with layer thickness of between 50 and 100 µm using a ps-pulsed laser are reported. It is shown that thin film sizes of around 50 µm could be structured, joined, and cut successfully using ultrafast lasers emitting in the NIR spectral range. Full article

(This article belongs to the Special Issue Design, Processes and Materials for Additive Manufacturing: 2nd Edition)

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18 pages, 8096 KiB

Open AccessArticle

Improved Microstructure Evolution and Corrosion Resistance in Friction-Welded Dissimilar AISI 1010/D3 Steel Joints Through Post-Weld Heat Treatment

by Rajesh Jesudoss Hynes Navasingh, T. Packiaraj Rajendran, Maria P. Nikolova, C P Goldin Priscilla, Piotr Niesłony and Krzysztof Żak

J. Manuf. Mater. Process. 2025, 9(4), 124; https://doi.org/10.3390/jmmp9040124 - 8 Apr 2025

Viewed by 240

Abstract

To achieve the desired material properties of automotive components made by friction welding, post-weld heat treatment is critical. The high temperatures encountered during the friction welding of steels can lead to changes in the microstructure, especially in the heat-affected zones. In the present [...] Read more.

To achieve the desired material properties of automotive components made by friction welding, post-weld heat treatment is critical. The high temperatures encountered during the friction welding of steels can lead to changes in the microstructure, especially in the heat-affected zones. In the present work, a D3 tool steel and an AISI1010 structural steel are friction welded by varying the rotational speed, and this is followed by post-weld heat treatment. Microstructural evaluation was performed on the friction-welded joints and those produced after heat treatment. Micrographs taken by scanning electron microscope show the formation of distinct zones with ultrafine grains at the interface. Zone measurements at the interfaces of the joints provide information on the proportions of the various zones formed during friction welding. Depending on the rotation speed, the width of the heat-affected zone (HAZ) can range from 10.8 to 19.5 mm, and the width of the total deformed zone varies from 700 to 1070 µm. The width of the fully plasticized zone is between 48 and 380 microns. The region of the friction-welded joint at 1600 rpm shows fine ferrite grains with a width of 48 µm FPDZ, which increase the strength of the joint according to the Hall–Petch equation. Primary carbides are dissolved in the ferrite matrix, and secondary carbides are formed due to the effects of alloying elements such as chromium in particular. Although the formation of secondary carbides cannot be prevented, at higher speeds the primary carbides are dissolved and the tendency to form secondary carbides is reduced. Post-weld heat treatment helps to redistribute these phases and leads to a more homogeneous material structure. The results show that post-weld heat treatment greatly improved the corrosion resistance of dissimilar AISI 1010/D3 steel joints produced by means of friction welding. Coarse grains have been eliminated, and thus the galvanic corrosion at the weld interface is alleviated and reduced. Post-weld heat treatment reduces the corrosion rate and weight loss significantly, by 54.8% and 60%. Full article

(This article belongs to the Special Issue Advances in Dissimilar Metal Joining and Welding)

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26 pages, 14205 KiB

Open AccessArticle

Cutting Fluid Effectiveness in the High-Speed Finish Machining of Inconel 718 Using a Whisker-Reinforced Ceramic Tool

by Walid Jomaa, Monzer Daoud, Hamid Javadi and Philippe Bocher

J. Manuf. Mater. Process. 2025, 9(4), 123; https://doi.org/10.3390/jmmp9040123 - 7 Apr 2025

Viewed by 322

Abstract

This paper aims to investigate the effectiveness of cutting fluid during the high-speed face-turning of superalloy Inconel 718 using chamfered whisker-reinforced ceramic inserts. It addresses this topic by providing a comprehensive understanding of the machinability of Inconel 718 under both dry and wet [...] Read more.

This paper aims to investigate the effectiveness of cutting fluid during the high-speed face-turning of superalloy Inconel 718 using chamfered whisker-reinforced ceramic inserts. It addresses this topic by providing a comprehensive understanding of the machinability of Inconel 718 under both dry and wet conditions through analytical friction modeling and a detailed analysis of the chip formation process. Two new indexes, named the Area Function (AF) and the Shape Function (SF), were derived to assess the serration intensity of the chips. Particular attention was paid to the interaction between the cutting speed and the cutting fluid. The results showed that wet conditions promote uniform chip formation, more stable forces, a lower coefficient of friction, and the absence of notch wear. At low cutting speed (60 m/min) and dry machining results in high serration intensity (SF = 0.7) and segmentation frequency (

f_{s e g}

= 22.08 kHz) compared to the SF of 0.4 and

f_{s e g}

= 19.69 kHz in wet conditions. The segmentation frequency increases significantly with cutting speed, reaching 71.03 kHz and 63.32 kHz at a cutting speed of 225 m/min for dry and wet conditions, respectively. It was also found that the rate of increase in the tangential force was lower (20.49 N/s) when using cutting fluid at a high cutting speed (225 m/min) compared to dry conditions (27.37 N/s). Full article

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15 pages, 6197 KiB

Open AccessArticle

Novel, High-Precision, On-Machine Approach for Measuring Cup Grinding Wheel Wear Using a Moveable Laser Displacement Sensor

by Chung-Ying Wang, Chien-Yao Huang and Yen-Han Chiang

J. Manuf. Mater. Process. 2025, 9(4), 122; https://doi.org/10.3390/jmmp9040122 - 7 Apr 2025

Viewed by 202

Abstract

This study developed a movable, high-precision laser measurement system for assessing wear on cup grinding wheels. The proposed setup employs a Keyence CL-P070 laser sensor with a resolution of 0.25 μm and has a simple installation process that supports flexible deployment on multiple [...] Read more.

This study developed a movable, high-precision laser measurement system for assessing wear on cup grinding wheels. The proposed setup employs a Keyence CL-P070 laser sensor with a resolution of 0.25 μm and has a simple installation process that supports flexible deployment on multiple workstations. Unlike traditional static configurations, the compact design requires minimal adjustment and enables versatile positioning across operational environments. An automated measurement procedure was developed that can capture changes in the grinding wheel profile between grinding cycles. The experimental results indicate that the proposed system has high repeatability and accuracy in detecting the subtle progression of wear in cup grinding wheels. The proposed approach provides a user-friendly on-machine measurement solution that can improve quality control and operational efficiency in industrial grinding processes. Full article

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21 pages, 4301 KiB

Open AccessArticle

Lean Service Waste Classification and Methodological Application in a Case Study

by Giuseppe Converso, Guido Guizzi, Emma Salatiello and Silvestro Vespoli

J. Manuf. Mater. Process. 2025, 9(4), 121; https://doi.org/10.3390/jmmp9040121 - 7 Apr 2025

Viewed by 237

Abstract

This study explores the application of Lean principles in the service sector, addressing the complexities of translating manufacturing-focused methodologies to intangible service activities. Lean Services, a relatively recent concept, lacks a standardised definition, leading to varied interpretations ranging from customer-centric approaches to waste [...] Read more.

This study explores the application of Lean principles in the service sector, addressing the complexities of translating manufacturing-focused methodologies to intangible service activities. Lean Services, a relatively recent concept, lacks a standardised definition, leading to varied interpretations ranging from customer-centric approaches to waste reduction strategies. Through a comprehensive literature review and a case study of a European scooter and motorcycle manufacturer, this research identifies a consolidated list of service-specific wastes, bridging a critical gap in Lean Services research. Additionally, the study compares two prominent methodologies—DMAIC (Define–Measure–Analyse–Improve–Control) from Six Sigma and the Cost Deployment pillar from World Class Manufacturing (WCM)—in the context of Lean Services. The analysis highlights DMAIC’s strength in advanced statistical tools and targeted problem-solving, contrasting with WCM’s systemic approach, emphasising economic feasibility and broader resource integration. By examining their individual and combined applicability, this research provides actionable insights for selecting methodologies based on specific objectives, time constraints, and resources. This work contributes to the evolving understanding of Lean Services, offering a framework for practitioners to enhance efficiency and drive continuous improvement in service-based processes. Full article

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14 pages, 6999 KiB

Open AccessArticle

Aluminium/Steel Joints with Dissimilar Thicknesses: Enhancement of UTS and Ductility Through Making an S-Shaped Interface and a Mixed-Mode Fracture

by Tiago Oliveira Gonçalves Teixeira, Reza Beygi, Ricardo João Camilo Carbas, Eduardo Andre Sousa Marques, Masih Bolhasani Hesari, Mohammad Mehdi Kasaei and Lucas Filipe Martins da Silva

J. Manuf. Mater. Process. 2025, 9(4), 120; https://doi.org/10.3390/jmmp9040120 - 5 Apr 2025

Viewed by 237

Abstract

This study presents a simple and innovative design to join a 2 mm thick steel sheet to a 5 mm thick aluminium sheet in a butt configuration. Thickness differences were addressed using support plates, while an aluminium run-on plate was employed to prevent [...] Read more.

This study presents a simple and innovative design to join a 2 mm thick steel sheet to a 5 mm thick aluminium sheet in a butt configuration. Thickness differences were addressed using support plates, while an aluminium run-on plate was employed to prevent the FSW tool from plunging into the steel. The process produced a unique S-shaped Al/St interface, the formation mechanism of which is analysed in this study. Scanning electron microscopy (SEM) observations revealed a gradient in the thickness of intermetallic compounds (IMCs) along the joint interface, decreasing from the top to the bottom. This S-shaped interface led to a 150% increase in the ultimate tensile strength (UTS) of the joint. The mechanism underlying this enhancement, attributed to the curved geometry of the interface and its alignment with the loading direction, is discussed in detail. These findings highlight the potential of this approach for improving the performance of dissimilar material joints in lightweight structural applications. Full article

(This article belongs to the Special Issue Advances in Dissimilar Metal Joining and Welding)

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16 pages, 4912 KiB

Open AccessArticle

Characterization of Laser-Ablated Bound Metal Deposition (laBMD)

by Alexander Watson, Masoud Rais-Rohani, John Belding, Jasper McGill and Brett D. Ellis

J. Manuf. Mater. Process. 2025, 9(4), 119; https://doi.org/10.3390/jmmp9040119 - 4 Apr 2025

Viewed by 315

Abstract

Additive manufacturing of metals is limited by a fundamental tradeoff between deposition rates and manufacturability of fine-scale features. To overcome this problem, a laser-ablated bound metal deposition (laBMD) process is demonstrated in which 3D-printed green-state bound metal deposition (BMD) parts are post-processed via [...] Read more.

Additive manufacturing of metals is limited by a fundamental tradeoff between deposition rates and manufacturability of fine-scale features. To overcome this problem, a laser-ablated bound metal deposition (laBMD) process is demonstrated in which 3D-printed green-state bound metal deposition (BMD) parts are post-processed via laser ablation prior to conventional BMD debinding and sintering. The laBMD process is experimentally characterized via a full-factorial design of experiments to determine the effect of five factors—number of laser passes (one pass, three passes), laser power (25%, 75%), scanning speed (50%, 100%), direction of laser travel (perpendicular, parallel), and laser resolution (600 dpi, 1200 dpi)—on as-sintered ablated depth, surface roughness, width, and angle between ablated and non-ablated regions. The as-sintered ablation depth/pass ranged from 3 to 122 µm/pass, the ablated surface roughness ranged from 3 to 79 µm, the angle between ablated and non-ablated regions ranged from 1° to 68°, and ablated bottom widths ranged from 729 to 1254 µm. This study provides novel insights into as-manufactured ablated geometries and surface finishes produced via laser ablation of polymer–metallic composites. The ability to inexpensively and accurately manufacture fine-scale features with tailorable geometric tolerances and surface finishes is important to a variety of applications, such as manufacturing molds for microfluidic devices. Full article

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11 pages, 3192 KiB

Open AccessArticle

Effect of Ball Milling Speeds on the Phase Formation and Optical Properties of α-ZnMoO₄ and ß-ZnMoO₄ Nanoparticles

by Maria Gancheva, Reni Iordanova, Petar Ivanov and Aneliya Yordanova

J. Manuf. Mater. Process. 2025, 9(4), 118; https://doi.org/10.3390/jmmp9040118 - 3 Apr 2025

Viewed by 234

Abstract

Two modifications of ZnMoO₄ were successfully obtained by mechanochemical treatment with two milling speeds applied at 500 and 850 rpm. The phase formation was monitored by XRD analysis. The metastable monoclinic ß-ZnMoO₄ was directly synthesized at room temperature using the higher [...] Read more.

Two modifications of ZnMoO₄ were successfully obtained by mechanochemical treatment with two milling speeds applied at 500 and 850 rpm. The phase formation was monitored by XRD analysis. The metastable monoclinic ß-ZnMoO₄ was directly synthesized at room temperature using the higher milling speed of 850 rpm. The thermodynamically stable triclinic α-ZnMoO₄ was obtained by combining heat treatment t 600 °C and ball milling at the lower milling speed of 500 rpm. The IR spectra contain typical vibration bands and confirm the formation of both ZnMoO₄ polymorphs. UV-Vis absorption and photoluminescence (PL) spectroscopy are used to study the optical properties of the as-prepared samples. The calculated optical band gaps for α- and ß-ZnMoO₄ are 4.09 and 3.02 eV. The photoluminescence emission spectrum of both samples shows peaks with different maximum intensity at 615 and 403 nm for α and ß phase, respectively. CIE co-ordinates are located in the orange and blue range of the color diagram. Full article

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13 pages, 3503 KiB

Open AccessArticle

Effects of Mixing Speed and Mixing Time on Powder Segregation During Powder Mixing for Binder Jetting Additive Manufacturing: An Experimental Study

by Mostafa Meraj Pasha, Zhijian Pei, Md Shakil Arman, Charles J. Gasdaska and Yi-Tang Kao

J. Manuf. Mater. Process. 2025, 9(4), 117; https://doi.org/10.3390/jmmp9040117 - 3 Apr 2025

Cited by 1 | Viewed by 342

Abstract

The binder jetting additive manufacturing process offers the ability to create three-dimensional parts layer by layer. However, using any powder that contains particles with different sizes, shapes, or densities can lead to powder segregation during the mixing, dispensing, and spreading steps of the [...] Read more.

The binder jetting additive manufacturing process offers the ability to create three-dimensional parts layer by layer. However, using any powder that contains particles with different sizes, shapes, or densities can lead to powder segregation during the mixing, dispensing, and spreading steps of the binder jetting additive manufacturing process. Powder segregation can often lead to uneven powder distribution across the powder bed, potentially causing defects in final parts. Therefore, it is important to understand powder segregation in mixing, dispensing, and spreading. Reported studies on powder segregation in mixing were conducted primarily on pharmaceutical or food powder that have different properties compared to metal or ceramic powder used in binder jetting additive manufacturing. There is a need for a deep understanding of how mixing speed and mixing time affect powder segregation in the context of binder jetting additive manufacturing. This paper reports an experimental investigation using a two-variable, two-level full-factorial design to examine the main effects and interaction effect of mixing speed and mixing time on powder segregation in the mixing of Powder A and Powder B for binder jetting additive manufacturing. The results reveal that segregation was more severe at the high level of mixing speed and the high level of mixing time. These findings provide useful insights for selecting mixing variables and controlling segregation, essential for achieving high-quality printed parts in binder jetting additive manufacturing. Full article

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16 pages, 3075 KiB

Open AccessArticle

Neural Network Optimization of Mechanical Properties of ABS-like Photopolymer Utilizing Stereolithography (SLA) 3D Printing

by Abdulkader Ali Abdulkader Kadauw

J. Manuf. Mater. Process. 2025, 9(4), 116; https://doi.org/10.3390/jmmp9040116 - 3 Apr 2025

Viewed by 335

Abstract

The optimization of mechanical properties in acrylonitrile butadiene styrene-like (ABS-like) photopolymer utilizing neural network techniques presents a promising methodology for enhancing the performance and strength of components fabricated through stereolithography (SLA) 3D printing. This approach uses machine learning algorithms to analyze and predict [...] Read more.

The optimization of mechanical properties in acrylonitrile butadiene styrene-like (ABS-like) photopolymer utilizing neural network techniques presents a promising methodology for enhancing the performance and strength of components fabricated through stereolithography (SLA) 3D printing. This approach uses machine learning algorithms to analyze and predict the relationships between various printing parameters and the resulting mechanical properties, thereby allowing the engineering of better materials specifically designed for targeted applications. Artificial neural networks (ANNs) can model complex, nonlinear relationships between process parameters and material properties better than traditional methods. This research constructed four ANN models to predict critical mechanical properties, such as tensile strength, yield strength, shore D hardness, and surface roughness, based on SLA 3D printer parameters. The parameters used were orientation, lifting speed, lifting distance, and exposure time. The constructed models showed good predictive capabilities, with correlation coefficients of 0.98798 for tensile strength, 0.9879 for yield strength, 0.9823 for Shore D hardness, and 0.98689 for surface roughness. These high correlation values revealed the effectiveness of ANNs in capturing the intricate dependencies within the SLA process. Also, multi-objective optimization was conducted using these models to find the SLA printer’s optimum parameter combination to achieve optimal mechanical properties. The optimization results showed that the best combination is Edge orientation, lifting speed of 90.6962 mm/min, lifting distance of 4.8483 mm, and exposure time of 4.8152 s, resulting in a tensile strength of 40.4479 MPa, yield strength of 32.2998 MPa, Shore D hardness of 66.4146, and Ra roughness of 0.8994. This study highlights the scientific novelty of applying ANN to SLA 3D printing, offering a robust framework for enhancing mechanical strength and dimensional accuracy, thus marking a significant benefit of using ANN tools rather than traditional methods. Full article

(This article belongs to the Special Issue Recent Advances in Optimization of Additive Manufacturing Processes)

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20 pages, 5173 KiB

Open AccessArticle

Scarf Adhesive Bonding of 3D-Printed Polymer Structures

by Tiago F. R. Ribeiro, Raul D. S. G. Campilho, Ricardo F. R. Pinto and Ricardo J. B. Rocha

J. Manuf. Mater. Process. 2025, 9(4), 115; https://doi.org/10.3390/jmmp9040115 - 2 Apr 2025

Viewed by 282

Abstract

Additive manufacturing (AM) has swiftly emerged as a substitute for conventional methods such as machining and injection moulding. Its appeal is attributed to accelerated prototyping, improved sustainability, and the capacity to fabricate intricate shapes. Nonetheless, the size constraints of additive manufacturing components require [...] Read more.

Additive manufacturing (AM) has swiftly emerged as a substitute for conventional methods such as machining and injection moulding. Its appeal is attributed to accelerated prototyping, improved sustainability, and the capacity to fabricate intricate shapes. Nonetheless, the size constraints of additive manufacturing components require the assembly of smaller 3D-printed elements to create larger structures. This study investigates the tensile properties of scarf joints (SJs) created from several polymers, including ABS, PETG, and PLA, adhered with Araldite^® 2015 and Sikaforce^® 7752 adhesives. The characteristics of the adherends were assessed prior to examining the adhesive efficacy in the SJ configuration. Experimental evaluations quantified failure modes, joint strength, assembly stiffness, and energy at failure, comparing findings with predictions from a cohesive zone model (CZM). The objective was to determine the ideal combination of materials and adhesives for enhanced joint performance. Results indicated that joint performance is greatly affected by the adherend material, adhesive selection, and scarf angle. PLA and Araldite^® 2015 typically exhibited optimal strength and stiffness, but Sikaforce^® 7752 demonstrated enhanced energy absorption for extended bonding lengths. Full article

(This article belongs to the Special Issue Innovative and Sustainable Advances in Polymer Composites for Additive Manufacturing: Processing, Microstructure, Machining, and Mechanical Properties)

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15 pages, 8851 KiB

Open AccessArticle

Directed Energy Deposition-Laser Beam of Semi-Austenitic Precipitation-Hardening Stainless Steel

by Alex Lourenço Barbosa, Fábio Edson Mariani, Fernanda Mariano Pereira, Osvaldo Mitsuyuki Cintho, Reginaldo Teixeira Coelho, Piter Gargarella and Kahl Zilnyk

J. Manuf. Mater. Process. 2025, 9(4), 114; https://doi.org/10.3390/jmmp9040114 - 29 Mar 2025

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Abstract

Directed Energy Deposition-Laser Beam (DED-LB) is an ideal Additive Manufacturing (AM) process to obtain very complex geometries, which can be important for several applications in industries such as aerospace and biomedical engineering. The present study aims to determine optimized DED-LB parameters for printing [...] Read more.

Directed Energy Deposition-Laser Beam (DED-LB) is an ideal Additive Manufacturing (AM) process to obtain very complex geometries, which can be important for several applications in industries such as aerospace and biomedical engineering. The present study aims to determine optimized DED-LB parameters for printing 17-7 PH stainless steel, a semi-austenitic precipitation-hardening alloy renowned for its exceptional combination of high yield strength, toughness, and corrosion resistance. The experimental work used different combinations of laser power, scanning speed, and powder feed rate to investigate the effects on the morphology, surface roughness, and microstructure of the deposited material. The results indicated that a powder feed rate of 4.7 g/min yielded uniform beads, reduced surface roughness, and increased substrate dilution, enhancing the metallurgical bond between the bead and substrate. Conversely, higher feed rates, such as a rate of 9.2 g/min, resulted in increased surface irregularities due to an excessive amount of partially melted powder particles. Microstructural analysis, supported by thermodynamic calculations, confirmed a ferritic–austenitic solidification mode. The austenite and ferrite fractions varied significantly, depending mainly on the substrate dilution due to the decrease in aluminum content. The combination of 400 W laser power and a 2000 mm/min scanning speed resulted in the optimal set of parameters, with an approximately 30% dilution and 80% austenite. Full article

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13 pages, 3544 KiB

Open AccessArticle

Mechanical Properties and Accuracy of Additively Manufactured Silicone Soft Tissue Materials

by Pei Xin Chen, John M. Aarts and Joanne Jung Eun Choi

J. Manuf. Mater. Process. 2025, 9(4), 113; https://doi.org/10.3390/jmmp9040113 - 28 Mar 2025

Viewed by 169

Abstract

The objective of this study was to measure and compare the mechanical properties of conventional and three additively manufactured soft tissue silicone materials, while evaluating the precision of additively manufactured (AMed) materials through different printing angles. Three additively manufactured soft tissue silicone materials [...] Read more.

The objective of this study was to measure and compare the mechanical properties of conventional and three additively manufactured soft tissue silicone materials, while evaluating the precision of additively manufactured (AMed) materials through different printing angles. Three additively manufactured soft tissue silicone materials were used, in addition to one conventional self-curing injectable silicone material as a control. AMed materials were divided into three groups with three build angles. Mechanical testing was conducted for tensile and compressive strength by a universal testing machine and Shore A hardness by a durometer. Accuracy analysis of additively manufactured materials (n = 20/group) was performed following superimposition and root mean square (RMS) calculation. Statistical differences between the groups were assessed with a one-way analysis of variance (ANOVA) and Tukey’s post hoc test at a significance level of p < 0.05. Scanning Electron Microscopy (SEM) analysis was performed for fracture surface analyses. The tensile strength of all additively manufactured silicone soft tissue materials was significantly lower (p < 0.0001) than that of the control material. All additively manufactured soft tissue material groups had significantly higher compressive strengths (p < 0.0001) and Shore A hardness values. Accuracy analysis showed no significant difference between the groups when compared at the same printing angle (0°, 45°, and 90°); however, within each material group, printing at 45° had higher RMS values than specimens printed at an angle of 0° and 90°. The conventional soft tissue material (control) had a significantly higher tensile strength than all the AMed soft tissue materials, whereas the opposite trend was found for flexural strength and shore hardness. When selecting an AMed material for soft tissue casts used during implant restoration fabrication, it is recommended to print the soft tissues at either 0° or 90°. Full article

(This article belongs to the Special Issue Advances in 3D Printing Technologies: Materials, Processes, and Applications)

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27 pages, 22605 KiB

Open AccessArticle

Slicing Solutions for Wire Arc Additive Manufacturing

by Michael Sebok, Canhai Lai, Chris Masuo, Alex Walters, William Carter, Nathan Lambert, Luke Meyer, Jake Officer, Alex Roschli, Joshua Vaughan and Andrzej Nycz

J. Manuf. Mater. Process. 2025, 9(4), 112; https://doi.org/10.3390/jmmp9040112 - 28 Mar 2025

Cited by 1 | Viewed by 521

Abstract

Both commercial and research applications of wire arc additive manufacturing (WAAM) have seen considerable growth in the additive manufacturing of metallic components. However, there remains a clear lack of a unified paradigm for toolpath generation when slicing parts for WAAM deposition. Existing toolpath [...] Read more.

Both commercial and research applications of wire arc additive manufacturing (WAAM) have seen considerable growth in the additive manufacturing of metallic components. However, there remains a clear lack of a unified paradigm for toolpath generation when slicing parts for WAAM deposition. Existing toolpath generation options typically lack the appropriate features to account for all complexities of the WAAM process. This manuscript explores the key slicing challenges specific to toolpaths for WAAM geometry and pairs each consideration with multiple solutions to mitigate most negative effects on completed components. These challenges must be addressed to minimize voids, prevent bead collapse, and ensure deposited components accurately approximate the desired geometry. Slicing considerations are grouped into four general categories: geometric, process, thermal, and productivity. Geometric considerations are addressed with overhang compensation, corner-sharpening, and toolpath-smoothing features. Process considerations are addressed with start point configuration and controls for the bead lengths and end points. Thermal and productivity considerations are addressed with island optimization, multi-material printing, and connected insets. Finally, tools for the post-processing of generated G-code are explored. Overall, these solutions represent a critical set of slicing features used to improve generated toolpaths and the quality of the components deposited with those toolpaths. Full article

(This article belongs to the Special Issue Advancing Wire Arc Additive Manufacturing (WAAM) for Metallic Component Manufacture: Recent Developments and Challenges)

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13 pages, 36645 KiB

Open AccessArticle

Melt Electrowritten Biodegradable Mesh Implants with Auxetic Designs for Pelvic Organ Prolapse Repair

by Nuno Miguel Ferreira, Evangelia Antoniadi, Ana Telma Silva, António Silva, Marco Parente, António Fernandes and Elisabete Silva

J. Manuf. Mater. Process. 2025, 9(4), 111; https://doi.org/10.3390/jmmp9040111 - 28 Mar 2025

Viewed by 250

Abstract

Pelvic organ prolapse (POP) is a common condition among women, characterized by the descent of pelvic organs through the vaginal canal. Although traditional synthetic meshes are widely utilized, they are associated with complications such as erosion, infection, and tissue rejection. This study explores [...] Read more.

Pelvic organ prolapse (POP) is a common condition among women, characterized by the descent of pelvic organs through the vaginal canal. Although traditional synthetic meshes are widely utilized, they are associated with complications such as erosion, infection, and tissue rejection. This study explores the design and fabrication of biodegradable auxetic implants using polycaprolactone and melt electrowriting technology, with the goal of developing implants that closely replicate the mechanical behavior of vaginal tissue while minimizing implant-related complications. Four distinct auxetic mesh geometries—re-entrant Evans, Lozenge grid, square grid, and three-star honeycomb—were fabricated with a 160

μ

m diameter and mechanically evaluated through uniaxial tensile testing. The results indicate that the square grid and three-star honeycomb geometries exhibit hyperelastic-like behavior, closely mimicking the stress–strain response of vaginal tissue. The re-entrant Evans geometry has been observed to exhibit excessive stiffness for applications related to POP, primarily due to material overlap. This geometry demonstrates stiffness that is approximately five times greater than that of the square grid or the three-star honeycomb configurations, which contributes to an increase in local rigidity. The unique auxetic properties of these structures prevent the bundling effect observed in synthetic meshes, promoting improved load distribution and minimizing the risk of tissue compression. Additionally, increasing the extrusion diameter has been identified as a promising strategy for further refining the biomechanical properties of these meshes. These findings lay a solid foundation for the development of next-generation biodegradable implants. Full article

(This article belongs to the Special Issue Advances in 3D Printing Technologies: Materials, Processes, and Applications)

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14 pages, 4577 KiB

Open AccessArticle

Evolution of Microstructure, Phase Composition, and Mechanical Properties During Thermomechanical Treatment of Co-Cr-Mo Alloy

by Tatiana Kin, Yury Gamin, Sergei Galkin, Abdullah Mahmoud Alhaj Ali, Anna Khakimova and Alexander Skugorev

J. Manuf. Mater. Process. 2025, 9(4), 110; https://doi.org/10.3390/jmmp9040110 - 27 Mar 2025

Viewed by 260

Abstract

Co-Cr-Mo alloys are in high demand as materials for medical implants. However, hot processing of these alloys is quite difficult due to the need to maintain narrow temperature range of deformation to achieve the required mechanical properties and structure of the products. The [...] Read more.

Co-Cr-Mo alloys are in high demand as materials for medical implants. However, hot processing of these alloys is quite difficult due to the need to maintain narrow temperature range of deformation to achieve the required mechanical properties and structure of the products. The features of formation of structure, phase composition and mechanical properties of Co-Cr-Mo alloy at the main stages of thermomechanical treatment were considered in this study. The results demonstrated a significant enhancement in the strength characteristics of the alloy during processing in both forging and radial shear rolling (RSR). At the same time, radial shear rolling processing simultaneously increased the strength and ductility of the alloy. According to the XRD analysis data, the phase composition changes from single-phase structure (FCC-phase) after forging to a mixture of FCC-phase and HCP-phase after RSR during processing. The structure gradient characteristic of RSR decreased as the total elongation ratio increased, maintaining a tendency towards a finer-grained structure near the surface of the bars and a coarser one in the center. This tendency was reflected in the average grain size and the level of mechanical properties. Combined thermomechanical treatment, including the RSR process, made it possible to achieve a unique formation of microstructure and phase composition in the Co-Cr-Mo alloy, ensuring high strength while maintaining ductility. Full article

(This article belongs to the Special Issue Deformation and Mechanical Behavior of Metals and Alloys)

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26 pages, 3292 KiB

Open AccessArticle

Additive Manufacturing of Copper—A Survey on Current Needs and Challenges

by Moritz Benedikt Schäfle, Michel Fett, Julian Gärtner and Eckhard Kirchner

J. Manuf. Mater. Process. 2025, 9(4), 109; https://doi.org/10.3390/jmmp9040109 - 27 Mar 2025

Viewed by 432

Abstract

Additive manufacturing (AM) of copper is subject to dynamic development regarding available processes and the quality of produced parts. While challenging, AM processes for copper provide parts with a quality comparable to other metallic material groups like steels. The reasons for the lower [...] Read more.

Additive manufacturing (AM) of copper is subject to dynamic development regarding available processes and the quality of produced parts. While challenging, AM processes for copper provide parts with a quality comparable to other metallic material groups like steels. The reasons for the lower prevalence of additive manufacturing of copper components in industrial applications are currently not sufficiently researched, especially in light of the significant progress made in the maturity of this technology. A survey is used to investigate the assessments of protagonists in the field of copper AM. The needs of current and potential users of copper AM are analyzed and outlined. This study reveals that the most relevant technical limitation for users is the reduced surface quality of parts, while overall processes need to become less costly and more reliable to find broader use. Answers given hint to a higher degree of automation, the possibility of multi-material processing, and the upscaling of machine and part sizes as relevant future trends in the copper AM sector. Full article

(This article belongs to the Special Issue Additive Manufacturing of Copper-Based Alloys)

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J. Manuf. Mater. Process., Volume 9, Issue 4 (April 2025) – 35 articles

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