Journal Description
Metals
Metals
is an international, peer-reviewed, open access journal published monthly online by MDPI. The Portuguese Society of Materials (SPM), and the Spanish Materials Society (SOCIEMAT) are affiliated with Metals and their members receive a discount on the article processing charges.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, SCIE (Web of Science), Inspec, CAPlus / SciFinder, and other databases.
- Journal Rank: JCR - Q2 (Metallurgy & Metallurgical Engineering) / CiteScore - Q1 (Metals and Alloys)
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 15 days after submission; acceptance to publication is undertaken in 2.7 days (median values for papers published in this journal in the second half of 2023).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
- Companion journals for Metals include: Compounds and Alloys.
Impact Factor:
2.9 (2022);
5-Year Impact Factor:
2.9 (2022)
Latest Articles
Effect of Al2O3 on Crystallization, Microstructure, and Properties of Glass Ceramics Based on Lead Fuming Furnace-Slag
Metals 2024, 14(6), 628; https://doi.org/10.3390/met14060628 (registering DOI) - 25 May 2024
Abstract
In the paper, glass ceramics used as architectural materials were prepared based on lead fuming furnace-slag (LFFS) by a synergistic sinter-crystallization method. The effects of Al2O3 addition on the crystallization phase, crystallization kinetics, and mechanical performance of glass ceramics were
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In the paper, glass ceramics used as architectural materials were prepared based on lead fuming furnace-slag (LFFS) by a synergistic sinter-crystallization method. The effects of Al2O3 addition on the crystallization phase, crystallization kinetics, and mechanical performance of glass ceramics were investigated. The results showed that the phases of the glass ceramics prepared were composed of gehlenite and wollastonite, and crystallization kinetics analysis showed that bulk crystallization dominated the overall crystallization process in the Al2O3 content range from 2% to 8%. The glass transition temperature and the crystallization peak temperature of the glass ceramics generally increased with the increase in the Al2O3 content. Additionally, the crystalline morphology gradually developed from sheet-like to spherical, while the number of pores increased and the bulk density gradually decreased. When the Al2O3 content was 2%, the bending strength of glass ceramics reached its maximum, 75.1 MPa, corresponding to a bulk density of 2.24 g·cm−3. Owing to the high strength and relatively low bulk density, the sintered glass ceramics appear promising for potential applications in lightweight construction tiles.
Full article
Open AccessArticle
Preparation of Two Novel Stable Silica-Based Adsorbents for Selective Separation of Sr from Concentrated Nitric Acid Solution
by
Chang Liu, Shichang Zhang, Xinpeng Wang, Lifeng Chen, Xiangbiao Yin, Mohammed F. Hamza, Yuezhou Wei and Shunyan Ning
Metals 2024, 14(6), 627; https://doi.org/10.3390/met14060627 (registering DOI) - 25 May 2024
Abstract
Crown ethers are famous for the highly selectively grab Sr(II) from concentrated nitric acid solution due to the size match, but they suffer from the high leakage into the liquid phase caused by the presence of a large number of hydrophilic groups. To
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Crown ethers are famous for the highly selectively grab Sr(II) from concentrated nitric acid solution due to the size match, but they suffer from the high leakage into the liquid phase caused by the presence of a large number of hydrophilic groups. To reduce their leakage, two novel porous silica-based adsorbents, (DtBuCH18C6 + Dodec)/SiAaC-g-ABSA and (DtBuCH18C6 + Dodec)/SiAaC-g-3-ABSA, were prepared by vacuum impregnation with organic contents of about 55.9 wt.% and 56.1 wt.%, respectively. The two adsorbents have good reusability and structural stability, and the total organic carbon leakage rates in 2 M HNO3 solution are lower than 0.56 wt.% and 0.29 wt.%, respectively. Batch adsorption experiments revealed that the two adsorbents possessed good adsorption selectivity towards Sr, with SFSr/M over 40, except that of SFSr/Ba in 2 M HNO3 solution. The adsorption equilibrium of Sr in 2 M HNO3 solution was reached within 1 h, with saturated adsorption capacities of 36.9 mg/g and 37.5 mg/g, respectively. Furthermore, the XPS results indicate that the adsorption mechanism is the coordination of the crown ether ring with Sr. This work not only develops two novel adsorbents for the separation of Sr in nitric acid environments; it also provides a method for effectively reducing the water solubility of crown ethers.
Full article
(This article belongs to the Special Issue Advanced Sorbents for Separation of Metal Ions)
Open AccessArticle
Analysis of Inclusions and Impurities Present in Typical HPDC, Stamping and Extrusion Alloys Produced with Different Scrap Levels
by
Manel da Silva, Jaume Pujante, Joanna Hrabia-Wiśnios, Bogusław Augustyn, Dawid Kapinos, Mateusz Węgrzyn and Sonia Boczkal
Metals 2024, 14(6), 626; https://doi.org/10.3390/met14060626 (registering DOI) - 25 May 2024
Abstract
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The European Green Deal poses a two-pronged challenge for the automotive industry: migrating to solutions based on light structures, requiring lightweight concepts and light materials, while at the same time avoiding dependence on the importation of these advanced materials. Aluminium alloys are lightweight
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The European Green Deal poses a two-pronged challenge for the automotive industry: migrating to solutions based on light structures, requiring lightweight concepts and light materials, while at the same time avoiding dependence on the importation of these advanced materials. Aluminium alloys are lightweight and cost-effective materials that can successfully meet the requirements of many structural applications; however, their production requires bauxite and other Critical Raw Materials (CRMs), such as Si and Mg. Aluminium alloys are fully recyclable, but scrap is usually contaminated and its use is related to an increment of impurities, tramp elements and undesired inclusions. Traditionally, the use of secondary alloys has been restricted to low-performance applications. The present work analyses the effect that the use of scrap has on the quantity of inclusions present in the alloy and on other properties relevant for material processing. This study was carried out using common alloys associated with three of the most common aluminium processes used in the car manufacturing industry: high-pressure die casting (HPDC) (AB-43500), extrusion (6063) and sheet metal forming (5754 and 6181). The reference alloys were mixed with different levels of scrap (0, 20, 40, 60, 80 and 100%), with an aim to keep the chemical composition as unaffected as possible. The inclusion level of the alloy was characterized using the Prefil Footprinter® test. In addition, the obtained materials, after being cast in an open mould, were subjected to metallographic characterization. Relevant properties were measured to assess the processability of the alloys for the corresponding transforming process using the flowability test for the HPDC alloy and high-temperature compression for the extrusion alloys. The results obtained suggest that the number of inclusions present in the melt highly increase with the amount of scrap used to produce the alloy. These inclusions are also related to a significant loss of flowability, but do not have a noticeable impact on microstructure.
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Open AccessArticle
Precipitation Thermodynamics in an Al–Zn–Mg Alloy with Different Grain Sizes
by
Zhen Wang, Siqi Huang, Wenkai Zhang, Shunqiang Li and Jizi Liu
Metals 2024, 14(6), 625; https://doi.org/10.3390/met14060625 (registering DOI) - 25 May 2024
Abstract
In order to gain insight into the influence of grain size on precipitation thermodynamics, bulk materials of coarse-grained (CG), ultrafine-grained (UFG) (with or without dislocations), and nanocrystalline (NC) 7075 Al alloy have been fabricated by solid solution treatment, equal-channel angular pressing (ECAP), or
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In order to gain insight into the influence of grain size on precipitation thermodynamics, bulk materials of coarse-grained (CG), ultrafine-grained (UFG) (with or without dislocations), and nanocrystalline (NC) 7075 Al alloy have been fabricated by solid solution treatment, equal-channel angular pressing (ECAP), or high-pressure torsion (HPT) processes. The precipitation behavior and the corresponding thermal phenomenon were studied by transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) heating. The results indicated that there are significant differences in precipitation thermodynamics among the four bulk materials. In the CG and UFG materials without dislocations, homogeneous nucleation is the primary precipitation mechanism. However, the nucleation of the GP zones is suppressed at lower temperatures due to a reduction in the number of residual vacancies and the supersaturation in the UFG interiors. This is attributed to the absorption of vacancies and solute atoms by a greater volume of grain boundaries. It can be observed that the greater the excess of vacancies remaining in grain interiors, the lower the temperature at which nucleation of GP zones occurs. Defect-assisted heterogeneous nucleation was identified as the predominant precipitation mechanism in the UFG materials with dislocations and the NC materials. These defects encompass dislocations, lattice distortions, and grain boundaries. The decomposition processes of solid solutions were found to be almost complete at a lower temperature. The presence of dislocations, lattice distortions, and grain boundaries enables solute atoms to diffuse at a much faster rate, significantly enhancing the precipitation rate and reducing the nucleation and formation energies of various precipitate phases.
Full article
(This article belongs to the Special Issue Advances in Casting, Thermomechanical and Heat Treatment of Aluminum Alloys: Second Edition)
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Open AccessCommunication
ACOM/TEM and EBSD Microstructure Characterization of ECAE-Processed Zirconium
by
Mychelle Vianna Pereira Companhoni, Além-mar Bernardes Gonçalves, Maurizio Ferrante, Vitor Sordi and André Luiz Pinto
Metals 2024, 14(6), 624; https://doi.org/10.3390/met14060624 (registering DOI) - 25 May 2024
Abstract
Materials produced through equal channel angular extrusion (ECAE) may offer enhanced mechanical properties over classic thermomechanical processing like extrusion or rolling. Conventional techniques such as electron backscatter diffraction (EBSD) may be insufficient to properly characterize the microstructure of these materials. Darkfield (DF) transmission
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Materials produced through equal channel angular extrusion (ECAE) may offer enhanced mechanical properties over classic thermomechanical processing like extrusion or rolling. Conventional techniques such as electron backscatter diffraction (EBSD) may be insufficient to properly characterize the microstructure of these materials. Darkfield (DF) transmission electron microscopy (TEM), on the other hand, may lead to erroneous conclusions with respect to grain size. In this work, zirconium was submitted to ECAE deformation through four passes in the Bc route at 350 °C. The microstructure was evaluated through FEG-SEM/EBSD (field emission gun–scanning electron microscopy), DF TEM, and ACOM/TEM (automated crystal orientation mapping in TEM). EBSD revealed that the microstructure was heterogeneous with a few large grains surrounded by a fine submicrometric structure, which was only partially resolved through this technique. The fine structure was, however, described through ACOM/TEM. DF TEM was revealed to be somewhat unreliable when the same region was evaluated through ACOM/TEM. Therefore, a combination of techniques seems to be required for proper characterization.
Full article
Open AccessArticle
Unlocking the Potential of Sebacate: Investigating Its Role in the Inhibition of Filiform Corrosion on Organic Coated Steel
by
Andrea Cristoforetti, Stefano Rossi, Flavio Deflorian and Michele Fedel
Metals 2024, 14(6), 623; https://doi.org/10.3390/met14060623 - 24 May 2024
Abstract
The study investigated the effect of sebacate as a corrosion inhibitor for acrylic-coated steel. Specifically, it examined its impact on mitigating a frequent case of paint delamination, known as filiform corrosion (FFC), through a chosen weathering test designed to stress the degradation of
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The study investigated the effect of sebacate as a corrosion inhibitor for acrylic-coated steel. Specifically, it examined its impact on mitigating a frequent case of paint delamination, known as filiform corrosion (FFC), through a chosen weathering test designed to stress the degradation of the produced samples. Sebacate was demonstrated to be an efficient organic molecule for enhancing the corrosion resistance of steel. This efficacy was evaluated through electrochemical characterization based on electrochemical impedance spectroscopy measurements and potentiodynamic polarization curves, including the application of an FFC susceptibility prediction methodology based on measurements obtained in FFC-simulated electrolytes. An inhibition efficiency of 98% was measured in near-neutral saline solutions compared to conditions lacking inhibitor presence. During FFC simulation, the primary effect observed was associated with a reduction in cathodic activity evolution. Furthermore, a significant reduction in corrosion creep evolution of 35% was found. These experimental findings aligned closely with the outcomes projected by the simulated investigations.
Full article
(This article belongs to the Special Issue Novel Insights and Advances in Steels and Cast Irons)
Open AccessArticle
Die Casting of Lightweight Thin Fin Heat Sink Using Al-25%Si
by
Toshio Haga and Hiroshi Fuse
Metals 2024, 14(6), 622; https://doi.org/10.3390/met14060622 - 24 May 2024
Abstract
The demand for lightweight and cost-effective heat sinks is increasing. A typical method for economically manufacturing complex-shape heat sinks is die casting. To reduce the weight of the die-cast heat sinks, thinning the fins and base is common practice. We experimented with casting
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The demand for lightweight and cost-effective heat sinks is increasing. A typical method for economically manufacturing complex-shape heat sinks is die casting. To reduce the weight of the die-cast heat sinks, thinning the fins and base is common practice. We experimented with casting heat sinks using Al-25%Si in a conventional die casting machine with the aim of economically producing thinner fins and bases. Compared with the aluminum alloy used in conventional die casting, Al-25%Si has superior fluidity, which is proven to be very useful for reducing the thickness of the fins and base. As a result, we successfully reduced the heat sink weight using Al-25%Si and a conventional die casting machine. To investigate the properties of the produced Al-25%Si thin fin heat sink, we compared the effects of fin thickness, fin height, number of fins, and base thickness on heat dissipation and weight reduction. Additionally, we compared the weight and heat dissipation properties with those of a commercial heat sink and found that our Al-25%Si heat sink maintains the same heat dissipation performance but for 35% lower weight.
Full article
(This article belongs to the Special Issue Advances in Casting, Thermomechanical and Heat Treatment of Aluminum Alloys: Second Edition)
Open AccessReview
Review on Environmentally Assisted Static and Fatigue Cracking of Al-Mg-Si-(Cu) Alloys
by
Tetiana Avramenko, Silvain Michel, Jan Kollender, Iurii Burda, Ulrik Hans and Christian Affolter
Metals 2024, 14(6), 621; https://doi.org/10.3390/met14060621 - 24 May 2024
Abstract
This paper reviews the relevant literature and covers the main aspects of the environmentally assisted cracking of Al-Mg-Si-(Cu) alloys. Apart from a brief overview of the major microstructural and mechanical properties, it presents research results on the corrosion sensitivity and stress corrosion susceptibility
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This paper reviews the relevant literature and covers the main aspects of the environmentally assisted cracking of Al-Mg-Si-(Cu) alloys. Apart from a brief overview of the major microstructural and mechanical properties, it presents research results on the corrosion sensitivity and stress corrosion susceptibility of Al-Mg-Si alloys. Possible mechanisms of stress corrosion cracking and corrosion fatigue in aluminum alloys, such as anodic dissolution and/or interaction with hydrogen, are considered. A number of factors, including atmospheric or solution conditions, applied stress, and material properties, can affect these mechanisms, leading to environmentally assisted cracking. Specific attention is given to Al-Mg-Si alloys with copper, which may increase the sensitivity to intergranular corrosion. The susceptibility to both intergranular corrosion and stress corrosion cracking of Cu-containing Al-Mg-Si alloys is mostly associated with a very thin layer (segregation) of Cu on the grain boundaries. However, the effect of Cu on the corrosion fatigue and fatigue crack growth rate of Al-Mg-Si alloys has received limited attention in the literature. At the current state of the research, it has not yet been holistically assessed, although a few studies have shown that a certain content of copper can improve the resistance of aluminum alloys to the environment with regard to corrosion fatigue. Furthermore, considerations of the synergistic actions of various factors remain essential for further studying environmentally assisted cracking phenomena in aluminum alloys.
Full article
(This article belongs to the Section Corrosion and Protection)
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Open AccessArticle
Compositional Design and Thermal Processing of a Novel Lead-Free Cu–Zn–Al–Sn Medium Entropy Brass Alloy
by
Spyridon Chaskis, Stavroula Maritsa, Paul Stavroulakis, Sofia Papadopoulou, Russell Goodall and Spyros Papaefthymiou
Metals 2024, 14(6), 620; https://doi.org/10.3390/met14060620 - 24 May 2024
Abstract
In the current work, a novel medium entropy copper alloy was designed with the aim of avoiding the use of expensive, hazardous or scarce alloying elements and instead employing widely available and cost-effective alternatives. In order to investigate this unknown region of multicomponent
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In the current work, a novel medium entropy copper alloy was designed with the aim of avoiding the use of expensive, hazardous or scarce alloying elements and instead employing widely available and cost-effective alternatives. In order to investigate this unknown region of multicomponent alloy compositions, the thermo-physical parameters were calculated and the CALPHAD method was utilized. This led to the design of the Cu50Zn25Al20Sn5 at. % (Cu53.45Zn27.49Al9.08Sn9.98 wt. %) alloy with a relatively low density of 6.86 g/cm3 compared with conventional brasses. The designed alloy was manufactured through vacuum induction melting, producing two ingots weighing 1.2 kg each, which were subjected to a series of heat treatments. The microstructural evolution of the alloy in the as-cast and heat-treated conditions was assessed through optical and scanning electron microscopy. The hardness of the as-cast and heat-treated alloy at room temperature was also studied. The alloy was characterized by a multiphase microstructure containing a major Cu-rich (Cu–Zn–Al) matrix reinforced with a secondary Zn-rich (Zn–Cu) phase and pure Sn. In terms of mechanical properties, the developed alloy exhibited high hardness values of roughly 378 HV0.2 and 499 HV0.2 in the as-cast and heat-treated conditions, respectively.
Full article
(This article belongs to the Special Issue Advances in Copper, Copper Alloys and Their Processing)
Open AccessArticle
Advanced FEM Insights into Pressure-Assisted Warm Single-Point Incremental Forming of Ti-6Al-4V Titanium Alloy Sheet Metal
by
Tomasz Trzepieciński, Marcin Szpunar, Robert Ostrowski, Waldemar Ziaja and Maciej Motyka
Metals 2024, 14(6), 619; https://doi.org/10.3390/met14060619 - 24 May 2024
Abstract
This study employs the finite element (FE) method to analyze the Incremental Sheet Forming (ISF) process of Ti-6Al-4V titanium alloy. The numerical modeling of pressure-assisted warm forming of Ti-6Al-4V sheets with combined oil-heating and friction stir rotation-assisted heating of the workpiece is presented
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This study employs the finite element (FE) method to analyze the Incremental Sheet Forming (ISF) process of Ti-6Al-4V titanium alloy. The numerical modeling of pressure-assisted warm forming of Ti-6Al-4V sheets with combined oil-heating and friction stir rotation-assisted heating of the workpiece is presented in this article. The thermo-mechanical FE-based numerical model took into account the characteristics of the mechanical properties of the sheet along with the temperature. The experimental conditions were replicated in FEM simulations conducted in Abaqus/Explicit, which incorporated boundary conditions and evaluated various mesh sizes for enhanced accuracy and efficiency. The simulation outcomes were compared with actual experimental results to validate the FE-based model’s predictive capacity. The maximum temperature of the tool measured using infrared camera was approximately 326 °C. Different mesh sizes were considered. The results of FEM modeling were experimentally validated based on axial forming force and thickness distribution measured using the ARGUS optical measuring system for non-contact acquisition of deformations. The greatest agreement between FEM results and the experimental result of the axial component of forming force was obtained for finite elements with a size of 1 mm. The maximum values of the axial component of forming force determined experimentally and numerically differ by approximately 8%. The variations of the forming force components and thickness distribution predicted by FEM are in good agreement with experimental measurements. The numerical model overestimated the wall thickness with an error of approximately 5%. By focusing on the heating techniques applied to Ti-6Al-4V titanium alloy sheet, this comparative analysis underlines the adaptability and precision of numerical analysis applied in modeling advanced manufacturing processes.
Full article
(This article belongs to the Special Issue Plastic Forming, Microstructure, and Property Optimization of Metals (Volume II))
Open AccessArticle
Research on Alloy Design and Process Optimization of Al–Mg–Zn-Cu-Based Aluminum Alloy Sheets for Automobiles with Secured Formability and Bake-Hardenability
by
GyeongSeok Joo, SeungGyu Choi, YoungKil Jung, SeHoon Kim and JaeHyuck Shin
Metals 2024, 14(6), 618; https://doi.org/10.3390/met14060618 - 24 May 2024
Abstract
In this study, the compositional design of high-formability, high-bake-hardening Al–Mg–Zn-Cu-based aluminum alloys was carried out, and process conditions were established to secure mechanical properties under harsh conditions for Al–Mg–Zn-Cu-based alloys. Using JMatPro13.0 for precipitation phase simulation, the optimal pre-aging temperature and time of
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In this study, the compositional design of high-formability, high-bake-hardening Al–Mg–Zn-Cu-based aluminum alloys was carried out, and process conditions were established to secure mechanical properties under harsh conditions for Al–Mg–Zn-Cu-based alloys. Using JMatPro13.0 for precipitation phase simulation, the optimal pre-aging temperature and time of the design composition were selected. Through the introduction of pre-aging, it was confirmed that no over-aging phenomena occurred, even after bake-hardening, and it was confirmed that it could have mechanical properties similar to those of test specimens subjected to traditional heat treatment. Through DSC (Differential Scanning Calorimetry) and TEM (Transmission Electron Microscope) analyses, it was found that pre-aging provided sufficient thermal stability to the GP (Guinier–Preston) zone and facilitated transformation to the η’-phase. In addition, it was confirmed that, even under bake-hardening conditions, coarsening of the precipitation phase was prevented and number density was increased, thereby contributing to improvements in the mechanical properties. The designed alloy plate was evaluated as having excellent anisotropy properties through n-value and -value calculations, and it was confirmed that a similar level of formability was secured through FLC (Forming Limit Curve) comparison with commercial plates.
Full article
(This article belongs to the Special Issue Advances in Casting, Thermomechanical and Heat Treatment of Aluminum Alloys: Second Edition)
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Open AccessArticle
Microstructural Evolution and Mechanical Behavior of Pure Aluminum Ultra-Thin Strip under Roller Vibration
by
Yang Zhang, Wenguang Li, Yijian Hu, Zhiquan Huang, Yan Peng and Zhibing Chu
Metals 2024, 14(6), 617; https://doi.org/10.3390/met14060617 - 24 May 2024
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As the demand for lithium-ion batteries increases, higher quality requirements are being placed on pure aluminum ultra-thin strips, one of the main materials used in lithium-ion battery current collectors. Roller vibration during the rolling process of pure aluminum ultra-thin strips is unavoidable and
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As the demand for lithium-ion batteries increases, higher quality requirements are being placed on pure aluminum ultra-thin strips, one of the main materials used in lithium-ion battery current collectors. Roller vibration during the rolling process of pure aluminum ultra-thin strips is unavoidable and significantly affects the quality of the strips. This paper uses 1A99 pure aluminum ultra-thin strips as raw materials and employs a controlled vibration method during the rolling process to obtain products under two conditions: stable rolling and vibrational rolling. The surface and cross-section of the aluminum strips were characterized using scanning electron microscopy (SEM), and the microstructure of the surface and cross-section was studied using electron backscatter diffraction (EBSD) technology. The results show that, during stable rolling, the surface quality of the aluminum strip is good without defects. Under vibration, obvious vibration marks appear on the surface of the aluminum strip, showing characteristics of peaks and troughs. With the increase in strain at the trough position, there is a transition from low-angle grain boundaries to high-angle grain boundaries, and the grain size is uneven at the peak and trough positions, with noticeable grain refinement at the troughs. At the same time, under the influence of vibration, the aluminum strip induces a different texture morphology from conventional rolling. Due to the different plastic strains at the peak and trough positions, a texture alternation phenomenon occurs at these positions. The tensile test results indicate that aluminum strips exhibit poor mechanical properties under roller vibration, with the reduction in mechanical performance primarily attributed to the uneven microstructure distribution caused by roller vibration.
Full article
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Open AccessArticle
Study and Optimization of the Punching Process of Steel Using the Johnson–Cook Damage Model
by
Adrián Claver, Andrea Hernández Acosta, Eneko Barba, Juan P. Fuertes, Alexia Torres, José A. García, Rodrigo Luri and Daniel Salcedo
Metals 2024, 14(6), 616; https://doi.org/10.3390/met14060616 - 23 May 2024
Abstract
Sheet metal forming processes are widely used in applications such as those in the automotive or aerospace industries. Among them, punching is of great interest due to its high productivity and low operating cost. However, it is necessary to optimize these processes and
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Sheet metal forming processes are widely used in applications such as those in the automotive or aerospace industries. Among them, punching is of great interest due to its high productivity and low operating cost. However, it is necessary to optimize these processes and adjust their parameters, such as clearance, shear force or tool geometry, to obtain the best finishes and minimize crack generation. Thus, the main objective of this research work is to optimize the punching process to achieve parts that do not require subsequent processes, such as deburring, by controlling the properties of the starting materials and with the help of tools such as design of experiments and simulations. In the present study, tensile tests were performed on three steels with different compositions and three sample geometries. The information obtained from these tests has allowed us to determine the parameters of the Johnson–Cook damage criteria. Moreover, punching was performed on real parts and compared with simulations to analyze the percentage of burnish surface. The results obtained show that the methodology used was correct and that it can be extrapolated to other types of die-cutting processes by reducing the percentage of surface fractures and predicting the appearance of cracks. Furthermore, it was observed that clearance has a greater influence than processing speed, while the minimum percentage of the burnish area was observed for the minimum values of clearance.
Full article
(This article belongs to the Special Issue Advances in Modeling and Simulation in Metal Forming)
Open AccessArticle
Effect of Electrolyte Temperature on Plasma Electrolytic Oxidation of Pure Aluminum
by
Yubing Cheng, Xuemei Shi, You Lv and Xinxin Zhang
Metals 2024, 14(6), 615; https://doi.org/10.3390/met14060615 - 23 May 2024
Abstract
Plasma electrolytic oxidation (PEO) is normally carried out under conditions with electrolyte cooling. However, the effect of the temperature of the electrolytes on the PEO behavior and properties of the resulting coatings is seldom investigated. In this study, PEO of pure Al was
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Plasma electrolytic oxidation (PEO) is normally carried out under conditions with electrolyte cooling. However, the effect of the temperature of the electrolytes on the PEO behavior and properties of the resulting coatings is seldom investigated. In this study, PEO of pure Al was carried out in a dilute aluminate electrolyte with the electrolyte temperature being controlled under low (~10–30 °C), medium (~40–50 °C) and high (~70–80 °C) temperature ranges, respectively. The morphology, microstructure, composition and phase component of the coatings fabricated under the different temperature ranges were analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The corrosion resistances of the coatings were evaluated by electrochemical methods. The hardness of the coatings and substrate following the PEO treatment in the different electrolyte temperature ranges were also tested. It was found that a higher electrolyte temperature resulted in a higher growth rate and rougher coatings. Moreover, the α-Al2O3 content was reduced as the electrolyte temperature increased. The highest corrosion resistance was registered for the coating obtained under the lowest temperature range, whereas the corrosion resistance of the coating obtained under the highest temperature range was the worst. The higher growth rate under high electrolyte temperatures was associated with the increased kinetics of the PEO reactions. However, the temperature of the electrolyte should be controlled under a suitable range to ensure reasonable coating properties.
Full article
Open AccessArticle
Efficient Implementation of the Binary Common Neighbor Analysis for Platinum-Based Intermetallics
by
Wenming Tang, Xianxian Zhang, Jianfeng Tang, Xingming Zhang, Liang Wang, Wangyu Hu and Lei Deng
Metals 2024, 14(6), 614; https://doi.org/10.3390/met14060614 - 23 May 2024
Abstract
The common neighbor analysis (CNA) for binary systems is a powerful method used to identify chemical ordering in intermetallics by unique indices. The capability of binary CNA, however, is largely restricted by the availability of indices for various ordered phases. In this study,
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The common neighbor analysis (CNA) for binary systems is a powerful method used to identify chemical ordering in intermetallics by unique indices. The capability of binary CNA, however, is largely restricted by the availability of indices for various ordered phases. In this study, CNA indices of 11 ordered phases derived from a face-centered cubic structure were introduced on a case-by-case basis. These phases, common in intermetallics containing platinum-group metals, include C11b, MoPt2, C6, B11, AgZr, A2B2[111], A2B2[113], Pt3Tc, A3B[011], A3B[111], and A3B[113]. The chemical order in static chemical perturbation, dynamic phase competition, and experimentally reconstructed nanophase alloys were identified using binary CNA. The results indicated that the proposed version of binary CNA exhibited significantly higher accuracy and robustness compared to the short-range order, polyhedral template matching, and the original binary CNA method. Benchmarked against available methods, the formation, decomposition, and competition of specifically ordered phases in bulks and nanoalloys were well reflected by present CNA, highlighting its potential as a robust and widely adopted tool for deciphering chemical ordering at the atomic level.
Full article
(This article belongs to the Section Computation and Simulation on Metals)
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Open AccessArticle
Optimization of Welded Joints under Fatigue Loadings
by
Paolo Livieri and Roberto Tovo
Metals 2024, 14(6), 613; https://doi.org/10.3390/met14060613 - 23 May 2024
Abstract
In this paper, the notch effect in weldments has been investigated, and the optimal configuration of different types of welded joints has been analysed using the implicit gradient approach. By considering this implicit gradient method, it is possible to calculate the effective stress
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In this paper, the notch effect in weldments has been investigated, and the optimal configuration of different types of welded joints has been analysed using the implicit gradient approach. By considering this implicit gradient method, it is possible to calculate the effective stress related to fatigue damage, with the effective stress being a continuous scalar function of the real stress tensor components, even in the presence of sharp edges. Hence, the search for the optimal configuration that maximises fatigue life can be tackled as the condition of minimum effective stress obtained by changing the weld shape and geometrical parameters. Both load-carrying cruciform joints and spot welds made of steel have been considered. The structural details have been studied by modelling actual shapes without any geometric simplification. Moreover, the same numerical procedure has been considered independently of the size, shape or load condition without imposing restrictive rules on the FE mesh.
Full article
(This article belongs to the Special Issue New Welding Materials and Green Joint Technology)
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Open AccessFeature PaperArticle
Analysis of a New Process for Forming Two Flanges Simultaneously in a Hollow Part by Extrusion with Two Moving Dies
by
Grzegorz Winiarski, Andrzej Gontarz, Andrzej Skrzat, Marta Wójcik and Sylwia Wencel
Metals 2024, 14(6), 612; https://doi.org/10.3390/met14060612 - 22 May 2024
Abstract
This paper presents a new method for forming flanges in hollow parts. The process consists of an extrusion with two dies that move in an opposite direction to that of the punches. This particular kinematics of the tools makes it possible to form
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This paper presents a new method for forming flanges in hollow parts. The process consists of an extrusion with two dies that move in an opposite direction to that of the punches. This particular kinematics of the tools makes it possible to form two flanges simultaneously in a single tool pass. The proposed method was investigated using a tube made of steel 42CrMo4. It was assumed that the extrusion would be conducted as a cold forming process at ambient temperature. Different diameters and heights of the impression made in the top and bottom dies were used. It was demonstrated that the main failure mode of the proposed technique was an unintended increase in the inside the diameter of the workpiece in the flange zone. The results showed that the above parameters had a key impact on the achievable maximum flange diameters and heights.
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(This article belongs to the Special Issue Advances in Modeling and Simulation in Metal Forming)
Open AccessArticle
Research on the Chloride Ion Corrosion Resistance of Cu-Sb-Added Low-Carbon Steel
by
Yuanyu Chen, Zhengbing Meng, Yuxiang Li and Jialong Shen
Metals 2024, 14(6), 611; https://doi.org/10.3390/met14060611 - 22 May 2024
Abstract
The corrosion resistance of low-carbon steel and two new low-alloy, corrosion-resistant steels containing Cu-Sb and Cu was studied in a simulated seawater environment. The effects of Cu and Sb on corrosion resistance were analyzed by an electrochemical test and accelerated corrosion test. The
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The corrosion resistance of low-carbon steel and two new low-alloy, corrosion-resistant steels containing Cu-Sb and Cu was studied in a simulated seawater environment. The effects of Cu and Sb on corrosion resistance were analyzed by an electrochemical test and accelerated corrosion test. The results show that Cu and Sb reduce the corrosion current density by increasing the corrosion potential and increasing the polarization resistance. Sb can promote the formation of Cu-containing compounds with a strong corrosion inhibition performance, and it can enhance the overall corrosion resistance of steel. In addition, Sb can also promote the conversion of Fe2+ ions into a corrosion-resistant compound, α-FeOOH, and it also further improves the corrosion resistance of steel.
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(This article belongs to the Special Issue Environmentally-Assisted Degradation of Metals and Alloys)
Open AccessArticle
Cracking Behavior of the ZhS6K Superalloy during Direct Laser Deposition with Induction Heating
by
Anastasiia Dmitrieva, Anastasiya Semenyuk, Margarita Klimova, Ilya Udin, Dmitrii Mukin, Artur Vildanov, Sergey Zherebtsov, Olga Klimova-Korsmik and Nikita Stepanov
Metals 2024, 14(6), 610; https://doi.org/10.3390/met14060610 - 22 May 2024
Abstract
For this work, the behavior of the ZhS6K alloy (Russian grade) in the process of direct laser deposition was investigated. Two samples, a “small” one (40 × 10 × 10 mm3) and “large” one (80 × 16 × 16 mm3
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For this work, the behavior of the ZhS6K alloy (Russian grade) in the process of direct laser deposition was investigated. Two samples, a “small” one (40 × 10 × 10 mm3) and “large” one (80 × 16 × 16 mm3), were fabricated with direct laser deposition. In both samples, the typical dual-phase γ/γ҆ microstructure with cuboidal shape of the γ҆ precipitates was observed. Both specimens revealed a similar tendency to continuous increasing in hardness from the bottom to the top associated with the refinement of γ҆ precipitates. The “small” sample was essentially crack-free, while the “large” one underwent extensive cracking. The possible effects of various factors, including thermal history, size, and shape of the gamma grains, on cracking behavior were discussed.
Full article
Open AccessArticle
Kinetics of HCP-BCC Phase Transition Boundary in Magnesium at High Pressure
by
Nitin P. Daphalapurkar
Metals 2024, 14(6), 609; https://doi.org/10.3390/met14060609 - 22 May 2024
Abstract
Under high pressures, many crystalline metals undergo solid–solid phase transformations. In order to accurately model the behavior of materials under extreme loading conditions, it is essential to understand the kinetics of phase transition. Using molecular dynamics simulations, this work demonstrates the feasibility of
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Under high pressures, many crystalline metals undergo solid–solid phase transformations. In order to accurately model the behavior of materials under extreme loading conditions, it is essential to understand the kinetics of phase transition. Using molecular dynamics simulations, this work demonstrates the feasibility of characterizing the speeds of a moving phase boundary using atomistic simulations employing a suitable empirical potential for single-crystal magnesium. The model can provide temperature- and tensorial stress-dependent velocity of a moving phase boundary as a rate-limiting contribution to the kinetics of phase transformation in continuum codes. Results demonstrate that a nonlinear interaction exists between plasticity and phase transition, facilitating a jump in the velocity of a moving phase boundary, facilitated by activated plastic deformation mechanisms.
Full article
(This article belongs to the Special Issue Dynamic Response of Metals under Extreme Conditions)
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