Article
Materials Science, Multidisciplinary
Nuo Lei, Guangzeng Zhang, Xuefeng Li, Shaojie Wu, Tan Wang, Yongfu Cai, Ran Wei, Shaokang Guan, Fushan Li, Chen Chen
Summary: A novel Fe2CrNiSi0.3Al0.28 high-entropy alloy (HEA) with a Co-free Fe-rich composition and a heterogeneous microstructure was successfully produced via arc-melting. The as-cast HEA exhibits outstanding mechanical properties, including a high ultimate tensile strength of 1.3 GPa and a reasonable plasticity of 9%, which surpass typical ductile HEAs. This research provides valuable insights for the further applications of HEAs.
Article
Materials Science, Multidisciplinary
Rong Qin, Rui-Fang Yan, Zhi-Ping Guan, Guang-Qi Zhang, Jia-Wang Song, Ming-Wen Ren, Jin-Guo Wang
Summary: The study explores the effects of V element addition on the microstructures, mechanical properties, and thermal conductivity of Al-8Si-0.1Cu-0.6Mg-0.7Fe hypoeutectic alloy in gravity die casting. It was found that V modification can influence the size of Fe-rich phases in the alloy, subsequently impacting the mechanical properties and thermal conductivity. Optimal levels of mechanical properties and thermal conductivity were achieved when the content of V element was 0.6%, as excessive V addition led to poor alloy properties.
MATERIALS RESEARCH EXPRESS
(2021)
Article
Chemistry, Physical
Vikas Shivam, Shubhada Kar, Gaurav K. Bansal, Avanish K. Chandan, Biraj K. Sahoo, G. K. Mandal, N. K. Mukhopadhyay, V. C. Srivastava
Summary: A cost-effective iron-rich non-equiatomic Fe50Mn20Al15Ni10Co5 medium entropy alloy (MEA) was synthesized by vacuum induction melting. The as-cast alloy exhibits a multiphase microstructure and has shown high compressive yield strength and ultimate strength, as well as good ductility. These results provide direction for designing and developing economically viable alloys at an industrial scale.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Shichao Liu, Shipeng Yue, Jinchuan Jie, Songsong Xu, Yong Dong, Bowen Dong, Xinzhong Li, Tingju Li
Summary: In this study, the intentional introduction of Si element into Cu-20Fe alloy was carried out to tailor the microstructure and properties. The effect of Si addition on the solidification microstructure and resultant properties of experimental Cu-20Fe-xSi alloys was systematically investigated. The addition of Si resulted in significant morphology change, refinement of Fe-rich phase, and influence on magnetic and mechanical properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Crystallography
Jingdong Li, Fanming Chen, Yuze Wang, Yuanliang Zhang, Rui Zhang, Yi Luo, Yiqiang He, Ke Sun, Lijie Zuo
Summary: The effects of Fe, Cr and thermal exposure on the microstructure and mechanical properties of Al-Si alloy were studied. The size and shape of the Fe-rich phase changed with the increase of Fe content. The mechanical properties of the alloys improved with the addition of Fe at elevated temperatures. However, the ductility and strength decreased at room temperature due to the presence of large and brittle Fe-rich phase.
Article
Chemistry, Physical
Kikang Lee, Jejun Jeong, Yeoneyi Chu, Jongbeom Kim, Kyuhwan Oh, Jeongtak Moon
Summary: In this study, structurally stable Fe-Si alloy powders were synthesized by high-energy milling, and it was found that the Fe-Si alloy powder after 12 hours of milling showed the best electrochemical properties. The low electrical conductivity and durability of β-FeSi2 were identified as the main factors contributing to the improved battery performance.
Article
Chemistry, Physical
Tomohiro Suetsuna, Hiroaki Kinouchi
Summary: A sintered Fe-Co-Si alloy with coherent precipitation of Ta3Co3C carbide particles is fabricated through a unique synthesis route. The carbide particles precipitate evenly on the surface, in the grain boundaries, and inside the grains of the matrix, contributing to improved mechanical strength. The alloy also exhibits excellent magnetic properties and mechanical properties compared to conventional materials.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Xu Liu, Cheng Wang, Shao-You Zhang, Jia-Wang Song, Xiao-Li Zhou, Min Zha, Hui-Yuan Wang
Summary: The formation of Fe-bearing phases in Al-0.53Mg-0.69Si-0.14Fe alloy under different casting processes was studied in this work. The promotion of the peritectic reaction in the TRC process led to the formation of pi-AlFeMgSi phase, while the DC process resulted in the formation of beta-AlFeSi phase. After homogenization treatment, the TRC sample exhibited higher yield strength than the DC sample due to the lower dissolution temperature of pi-AlFeMgSi phase.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Yinghan Ma, Chenglu Liu, Kesong Miao, Hao Wu, Rengeng Li, Xuewen Li, Guohua Fan
Summary: In this study, the Al-Mg-Si-Fe-Cr alloy was treated with water quenching and air quenching, and the mechanical properties and deformation behavior were investigated under different temperatures and microstructures. The results showed that the water quenched sample had higher yield strength and work hardening rate compared to the air quenched sample, and both samples exhibited improved strength and ductility at low temperatures. Electron back scatter diffraction analysis revealed different grain orientation evolution for the two samples, with the water quenched sample activating two slip systems at low temperature, while only one slip system was activated at high temperature. Transmission electron microscopy examination also indicated that the deformation in the precipitate-free zone was more severe for the air quenched sample at high temperature, while the deformation was more homogeneous for the air quenched sample at low temperature, leading to increased ductility.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
Abdollah Bahador, Junko Umeda, Ridvan Yamanoglu, Tuty Asma Abu Bakar, Katsuyoshi Kondoh
Summary: Fully dense powder metallurgy (PM) Ti-4Fe-0.2O-3Cu-0.4Si alloy was produced using spark plasma sintering (SPS) and hot extrusion to develop an inexpensive high strength dual-phase Ti alloy. The addition of Si solute remarkably enhanced the microstructure stability and yield strength of the alloy at high temperature. The principal strengthening mechanisms were grain refinement and solid solution phenomena, leading to a comparatively higher tensile strength of the alloy compared to conventional Ti-6Al-4V alloy produced by a similar method.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Xiaojun Shen, Huang Sheng, Yaojie He, Konstantinos A. Liogas, Kwang Boon Lau, Pei Wang, Fanbo Meng, Kewei Chen, Ning Jia, Upadrasta Ramamurty, Christopher H. T. Lee
Summary: This study focuses on using laser powder bed fusion technique to manufacture a soft magnetic core and explores its application in electric machines. The results show that the additively manufactured alloy performs better than traditional soft magnetic composite materials in weak magnetic fields, but further optimization is needed for strong magnetic fields and high-frequency applications.
MATERIALS & DESIGN
(2023)
Article
Materials Science, Multidisciplinary
Jiatong Li, Wanyuan Gui, Wenyi Peng, Yuxian Cao, Xiayan Wang, Zi Jin, Yang Yi, Yuhai Qu
Summary: Co-Cr-Fe-Ni-Ta eutectic multi-principal element alloys have the potential to replace structural alloys in engineering applications. In this study, a set of novel Fe55Cr15Ni30-xTax eutectic MPEAs were developed, and the effect of Ta on microstructure and compressive mechanical properties was investigated. The results showed that as the Ta content increases, the microstructure changes and the mechanical properties are affected.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Nanoscience & Nanotechnology
Xiaowen Sun, Yuefeng Wang, Dongyun Sun, Xin Jia, Ting Zhao, Fucheng Zhang, Tiansheng Wang
Summary: In this study, the microstructure and mechanical properties of Si-H13 nanobainite steel subjected to multi-tempering processes were investigated. The results showed that multi-tempering increased the yield strength and led to secondary hardening due to precipitation strengthening. However, the increase in thickness of bainitic ferrite laths was minimal.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Wenweijiao Wang, Yunhao Zhang, Haite Yang, Longshui Su, Chen Wang, Changqing Tong, Jianhui Zhou, Junfeng Chen, Bingshu Wang
Summary: This study investigated the effects of Si addition on the mechanical properties, electrical conductivity, and microstructure of CuCrZr alloy. The addition of Si element improved the hardness, strength, and ductility of CuCrZr alloy while slightly reducing the conductivity. Si element acted to refine the precipitation phases in the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Chemistry, Physical
Yuliang Zhao, Weixiang He, Judit Medina, Dongfu Song, Zhenzhong Sun, Yanlin Xue, G. Gonzalez-Doncel, R. Fernandez
Summary: The high temperature strengthening mechanisms in Al-Cu-Fe aluminium alloy were investigated through a comprehensive microstructural study and mechanical testing. It was found that Fe-rich phase particles play a significant role in strengthening through a load transfer mechanism, while the contribution of nanometric Al2CuMg precipitates is limited.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Materials Science, Multidisciplinary
Hyukjoon Kwon, Motoyuki Shiga, Hajime Kimizuka, Takuji Oda
Summary: The diffusion of hydrogen in metals is difficult to accurately measure due to surface and trapping effects, resulting in large deviations in reported experimental data. Computational studies have proposed atomistic simulation methods, but their accuracy remains questionable. This study used machine-learning moment tensor potentials with the accuracy of density functional theory to estimate the diffusivity of hydrogen in three bcc metals. The calculations showed excellent agreement with experimental data in the appropriate temperature range.
Article
Materials Science, Multidisciplinary
Masato Wakeda, Junji Saida
Summary: The cooling rate is a crucial factor in the formation of metallic glasses during the melt-quenching process. This study investigates the temperature- and thermal-history-dependent effects of cooling rate on the relaxation state of metallic glasses. Maps are constructed to demonstrate the effect of cooling rate on the quenching process as a function of temperature. Analyses of local atomic order and atomic dynamics reveal the atomistic origin of the temperature- and thermal-history-dependent effects of cooling rate. The physical background of the critical temperature range is discussed based on potential energy landscape and atomic dynamics.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Physics, Condensed Matter
Wei Guo, Tomoaki Niiyama, Rui Yamada, Masato Wakeda, Junji Saida
Summary: A novel thermal rejuvenation treatment facility for Zr-based bulk metallic glass (BMG) was developed, which involves rapid heating and indirect liquid nitrogen quenching. The reintroduction of free volume into the thermally rejuvenated BMG leads to a more disordered state. The rejuvenation process improves ductility by aiding in the recovery of shear transformation zone (STZ) site and volume.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2023)
Article
Metallurgy & Metallurgical Engineering
Takahito Ohmura, Masato Wakeda
Summary: The mechanical behaviors of metallic materials in a small scale have been characterized and modeled based on experimental measurements and computational simulation. The interaction between dislocation and grain boundary is considered, taking into account both geometrical and chemical factors. Molecular dynamic simulation reveals that the geometrical effect is influenced not only by misorientation but also by the dislocation character. TEM in-situ straining has the potential to directly measure the critical stress upon slip, as discussed based on both experimental results and atomistic simulation in bcc metals.
JOURNAL OF THE JAPAN INSTITUTE OF METALS AND MATERIALS
(2023)
Article
Metallurgy & Metallurgical Engineering
Takahito Ohmura, Masato Wakeda
Summary: The mechanical behaviors of metallic materials at small scales were studied using experimental measurements and computational simulation. The effect of in-solution carbon or silicon on plasticity initiation in iron was analyzed and characterized through nanoindentation pop-in phenomenon. The coherency at a ferrite-cementite interface significantly influenced plasticity initiation and macroscopic yielding behavior. The stability of austenite phase in TRIP steel was evaluated by analyzing indentation-induced deformation, revealing a constraint effect by an adjacent harder phase. Heterogeneous microstructures with bimodal grain size in fcc metals exhibited inhomogeneous mechanical behavior depending on the location of the fine microstructure. The plasticity of pure iron was analyzed using a statistical model, showing a Gaussian function in the early stage and a power-law function in the subsequent stage. Molecular Dynamics simulation characterized the elemental steps in plastic deformation of metallic glass, indicating that plasticity inhomogeneity depends on the initially inhomogeneous atomistic structure.
JOURNAL OF THE JAPAN INSTITUTE OF METALS AND MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Hongxian Xie, Gaobing Wei, Jun-Ping Du, Akio Ishii, Guanghong Lu, Peijun Yu, Shigenobu Ogata
Summary: This study examined the anti-twinning and deformation twinning of body-centered-cubic metals under shear loading. It found a novel two-layer-by-two-layer anti-twinning mechanism that generates finite shear displacement along specific atomic planes. The newly observed anti-twinning process has a lower energy barrier for twin nucleation and growth compared to the previously proposed layer-by-layer anti-twinning process.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Heting Liao, Hajime Kimizuka, Hiroshi Miyoshi, Shigenobu Ogata
Summary: In this study, the nucleation preference of coherent GP zones and semicoherent theta' nanoprecipitates in Al-Cu alloys were characterized using classical nucleation theory (CNT) and a machine-learning-based interatomic potential. The findings revealed the temperature and solute-concentration dependencies of the nucleation barriers of the nanoprecipitates, which determine the crossover temperatures for the formation of each precipitate. The predicted results were in good agreement with previous experimental observations. This study contributes to the understanding of nucleation forces in Al-Cu alloys and provides theoretical guidance for the optimal age-hardening response.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Rana Hossain, Hajime Kimizuka, Shigenobu Ogata
Summary: MAX phases are a unique class of atomically layered ceramics that deform plastically at room temperature due to highly mobile basal dislocations (BDs). In this study, a machine-learning-based spectral neighbor analysis potential (SNAP) was developed to simulate the edge, screw, and mixed BDs in a Ti3SiC2 MAX phase. The SNAP calculations reveal that the BD core structure exhibits significant asymmetry depending on the position of the weakly bonded Si layer. Undissociated BD cores are centered on Si layers and have lower mobility compared to partial BDs. The findings contribute to a deeper understanding of the atomic-level behavior of BDs and the deformation modes of crystals with layered structures.
PHYSICAL REVIEW MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Hiroshi Okuda, Kohei Kintsu, Shu Kurokawa, Masao Tabuchi, Hiroaki Nitani, Hajime Kimizuka, Shin-ichi Inoue, Michiaki Yamasaki, Yoshihito Kawamura
Summary: A coarse-grained picture of segregation layers in MgYZn alloys has been confirmed, where the layers are two-dimensional cluster systems bound in stacking faults. The use of EXAFS, small-angle X-ray scattering, and scanning tunneling microscopy showed that the atomic configurations around Y and Zn atoms in the segregation layers are identical, indicating the presence of L12 clusters. This fingerprint was observed in both bulk LPSO structures and dilute MgYZn alloys.
Article
Materials Science, Multidisciplinary
Masato Wakeda, Takahito Ohmura
Summary: This study evaluates the resistance for dislocation transmission across tilt/twist low-angle grain boundaries (LAGBs) and found that the twist LAGB is a stronger obstacle compared to the tilt LAGB. The barrier effect of the grain boundary (GB) on the transmission is stronger for the screw component than for the edge component. The dominant factors of the GB-strengthening effect in LAGB are the incident lattice dislocation type, the structure of GB dislocations, and dislocation-dislocation reactions.
COMPUTATIONAL MATERIALS SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
M. Ohno, Y. Chen, Y. Chinda, T. Mohri
Summary: The combination of electronic-structure calculations, the cluster-variation method, and the phase-field method was used to calculate the phase equilibria and microstructural evolution of the disorder-L10 transition in the Fe-Pt system. The calculated transition temperature was close to the experimental value, and the spinodal ordering temperature was determined. The microstructure showed preferential growth of ordered domains along the <100> direction and the development of an anisotropic morphology of an antiphase domain structure. The calculations provided an atomistic interpretation of this morphology, offering consistent first-principles multiscale calculations without any adjusting parameters.
Article
Nanoscience & Nanotechnology
Silvia Pomes, Nozomu Adachi, Masato Wakeda, Takahito Ohmura
Summary: This study found a precursor phenomenon to incipient plasticity before the first serration in Zr50Cu40Al10 at% bulk metallic glass via nanoindentation testing.
SCRIPTA MATERIALIA
(2023)
Article
Materials Science, Multidisciplinary
M. Wakeda, T. Osada, T. Ohmura
Summary: This study investigated the dynamics of superlattice edge dislocations in binary and ternary Ni-based alloys. The results showed that the effects of temperature and applied shear stress on dislocation motion are complex. At low shear stress, solute atoms disturb dislocation motion and temperature promotes it. On the other hand, at high shear stress, temperature suppresses dislocation motion due to the phonon drag effect.
MATERIALS TODAY COMMUNICATIONS
(2023)