Article
Materials Science, Multidisciplinary
Yueyue Yang, Shuang Zhang, Ping Huang, Fei Wang
Summary: The strengthening and strain hardening behaviors of a CoNiCrFeMn high-entropy alloy were investigated using molecular dynamics (MD) simulation. Two gradient structures, including grain size and composition gradient, were introduced into the alloy. The alloy exhibited a high strain hardening rate and distinct phase transformations, which were found to play crucial roles in determining the strengthening and unusual strain hardening behaviors. The microstructural evolution at increased strain was also discussed.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Dong Huang, Yanxin Zhuang
Summary: In this study, the coherent precipitation strengthening of L1(2) phase and Face-Centered Cubic (FCC) -Hexagonal Close-Packed (HCP) type martensitic transformation were successfully combined in a single alloy, resulting in increased yield strength and uniform elongation. The presence of L1(2) phase was found to directly affect the deformation mode of the alloy.
MATERIALS & DESIGN
(2022)
Article
Nanoscience & Nanotechnology
Benjamin Neding, Ye Tian, J. Y. Peter Ko, Peter Hedstrom
Summary: In-situ high-energy synchrotron X-ray diffraction experiments were performed to study the effect of temperature on the deformation behavior of a metastable austenitic stainless steel. The results showed that the temperature change caused significant variations in the deformation mechanism of the alloy.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Ravi Sankar Haridas, Priyanshi Agrawal, Rajiv S. Mishra
Summary: The mechanical response of TRIP-enabled metastable high entropy alloys is characterized by a constant work hardening segment followed by stages of gradual drop in work hardening under uniaxial tension. A four-parameter empirical model based on this work hardening curve has been developed and offers ease of identification from macroscopic mechanical response. Insights can be drawn from the model parameters when fitted to the tensile deformation response of TRIP HEAs, and a method to predict the tensile mechanical response based on correlated parameters with stacking fault energy and microstructure is proposed.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Lei Tang, Fuqing Jiang, Huibin Liu, Saurabh Kabra, Biao Cai
Summary: High manganese steels, with low production cost and potential for excellent strength-ductility combinations, are being recognized as promising structural materials for cryogenic applications. The addition of 1 wt% Cu to the steel effectively improves yield strength (YS) and elongation, and increases stacking fault energy (SFE), delaying the formation of martensite. At lower deformation temperatures, tensile strength increases linearly, while stacking faults and dislocations are promoted, and SFE decreases linearly. Contributions to YS and flow stress from lattice friction, grain boundary, dislocation, deformation twins, and phase transformation were determined.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Ravi Sankar Haridas, Priyanka Agrawal, Surekha Yadav, Priyanshi Agrawal, Anurag Gumaste, Rajiv S. Mishra
Summary: The excellent work hardening in TRIP-enabled metastable high entropy alloys is attributed to the phase transformation from austenite to martensite, as well as non-basal slip activity and deformation twinning. A five-parameter empirical model has been developed to replicate the work hardening rate in TRIP HEAs, with easy parameter identification compared to physically based models. The model parameters are correlated with stacking fault energy to predict the tensile stress-strain response of TRIP HEAs.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Hyun Chung, Dae Woong Kim, Woo Jin Cho, Heung Nam Han, Yuji Ikeda, Shoji Ishibashi, Fritz Kormann, Seok Su Sohn
Summary: High- and medium-entropy alloys with high solid-solution strength have significant effects on strain-hardening rate. In this study, the role of solid-solution strengthening on strain-hardening rate was revealed by controlling the Cr/V ratio in V1-xCrxCoNi alloys and investigating the evolution of deformation structures. The results showed that under the activated huge solid-solution strengthening effect, dislocation-mediated plasticity can be predominant over twinning, leading to an overall higher strain-hardening rate in the V-rich alloys.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Chemistry, Physical
You Sub Kim, Hobyung Chae, E-Wen Huang, Jayant Jain, Stefanus Harjo, Takuro Kawasaki, Sun Ig Hong, Soo Yeol Lee
Summary: In this study, a non-equiatomic high-entropy alloy with a stable solid solution and high stacking fault energy was successfully manufactured. The alloy exhibited a good combination of strength and ductility, which can be attributed to the active motion of dislocations and lattice distortion.
Article
Chemistry, Physical
Yubi Gao, Yutian Ding, Haifeng Li, Hongbiao Dong, Ruiyao Zhang, Jun Li, Quanshun Luo
Summary: The study found that grain refinement can enhance the elastic modulus and yield strength of Inconel 625 alloy, as well as improve the consistency of polycrystalline deformation. The deformation mechanism of coarse-grained samples is mainly influenced by stacking faults and dislocations, while fine-grained samples only involve dislocation slipping.
Article
Nanoscience & Nanotechnology
Suning Li, Philip J. Withers, Saurabh Kabra, Kun Yan
Summary: The microstructural evolution and deformation mechanisms of 316L stainless steel were studied at different temperatures using in situ neutron diffraction and transmission electron microscopy (TEM). It was found that the yield strength and ultimate tensile strength of the steel increase significantly at cryogenic temperatures. Deformation-induced martensitic transformation occurs at all cryogenic temperatures, accompanied by the appearance of e-martensite as an intermediate phase. The evolution of lattice strain, phase volume fraction, stacking fault probability, and stacking fault energy were quantified to investigate the correlation between deformation mechanisms and mechanical behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Chemistry, Physical
Yuanbo Zhou, Wenli Song, Fei Zhang, Yuan Wu, Zhifeng Lei, Meiyuan Jiao, Xiaobin Zhang, Jie Dong, Yibo Zhang, Ming Yang, Zhichao Lu, Stefanus Harjo, Takuro Kawasaki, Wu Gong, Yanchun Zhao, Dong Ma, Zhaoping Lu
Summary: The grain orientation-dependent lattice strain evolution in a (TiZrHfNb)98N2 alloy during tensile loading was investigated using in situ neutron diffraction. The alloy exhibited a relatively low strain-hardening rate, indicating weak work-hardening ability. Transmission electron microscopy revealed a dislocation planar slip mode confined to a few single-slip planes, leading to in-plane softening due to high pile-up stresses. During plastic deformation, <110>-oriented grains yielded first, followed by lattice relaxation, and then the load transferred to <200>-oriented grains due to plastic anisotropy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Engineering, Mechanical
Daixiu Wei, Wu Gong, Tomohito Tsuru, Takuro Kawasaki, Stefanus Harjo, Biao Cai, Peter K. Liaw, Hidemi Kato
Summary: This study investigated the yielding and hardening behaviors of high-entropy alloys (HEAs) using in situ neutron diffraction, first-principles method, and electron microscopy. The research found that high shear modulus and grain refinement can improve the yield strength of HEAs, while a larger dislocation density and stacking faults contribute to higher flow stresses and better ductility. Furthermore, low stacking fault energy promotes mechanical twinning and martensitic transformation, further enhancing the strain-hardening rate of HEAs.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Chemistry, Physical
Chun-Chieh Wang, Ji-Heng Chen, Jien-Wei Yeh, Su-Jien Lin, Shou-Yi Chang, Yu-Chieh Lo, Chao-Chun Yen, Kuan-Hao Lin, Chieh-Min Tseng, Tu-Ngoc Lam, Shin-An Chen, Chan-Sheng Wu, Chung-Kai Chang, Bi-Hsuan Lin, Mau-Tsu Tang, Hwo-Shuenn Sheu, Shi-Wei Chen, E-Wen Huang
Summary: The extraordinary dynamics of microstructures, such as various dislocations, stacking faults, twinning, and polymorphism transformations, dominate the mechanical performance of high-entropy alloys. The study reveals the influence of initial microstructure on stacking fault energy reduction and twinning formation, as well as the observation of twinning in the HCP phase of CoCrFeMnNi alloy under high pressure for the first time.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Prafull Pandey, Milan Heczko, Nikhil Khatavkar, Namrata Mazumder, Abhishek Sharma, Abhishek Singh, Michael J. Mills, Kamanio Chattopadhyay
Summary: This study reports an unprecedented precipitate shearing mechanism in CoNi-based superalloys at room temperature, which leads to significant work hardening rate. The observed twinning induced plasticity (TWIP) effect correlates with an excellent combination of yield strength, ultimate tensile strength (UTS) and plasticity. The deformation mechanism is directly correlated with the negative stacking fault energy of the matrix and low CSF energy of the gamma ' precipitates.
Article
Chemistry, Physical
Kailan Huang, Yang Zhang, Zhongwu Zhang, Yongzheng Yu, Junpeng Li, Jihong Han, Kai Dong, Peter K. Liaw, Ian Baker, Lixin Sun
Summary: A new high-entropy alloy with excellent strength and ductility has been developed in this study. The high yield strength and good ductility are achieved through the precipitation strengthening and phase transformation mechanism. The coupling of precipitation strengthening and TRIP effect provides a suitable strategy to overcome the trade-off between strength and ductility.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Husain Mehdi, R. S. Mishra
Summary: By utilizing multipass friction stir processing (MPFSP), the present work achieved homogeneously disseminated ZrB2 reinforcement particles and a very fine grain structure in AA6082. The influence of ZrB2 on the microstructure and tensile properties of MPFSP was observed. The study found that ZrB2 successfully shattered coarse dendrite clusters, resulting in a uniform microstructure. Additionally, ZrB2 particles inhibited grain boundary migration and led to a reduction in grain size and HAGBs fraction.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Materials Science, Multidisciplinary
N. Zhu, D. Z. Avery, Y. Chen, K. An, J. B. Jordon, P. G. Allison, L. N. Brewer
Summary: This study provides the first description of residual stress distributions in a 66-mm-thick AA6061 deposit produced by additive friction stir deposition (AFSD). The measurements showed that the longitudinal residual stresses were generally tensile, while the transverse residual stresses were smaller. Compressive residual stresses were present at the finishing end of the deposit. The measured residual stresses were homogeneously distributed throughout the deposit except for the top few layers.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Materials Science, Multidisciplinary
Yu-Wei Wang, Panagiotis Makrygiannis, Wei Wu, Sobhan Nazari Tiji, Feng Zhu, Jimmy Zhang, Grant A. Thomas, Ke An
Summary: The dependence of martensite phase transformation on deformation modes and strain paths in QP980 steel formed into a T-shape panel was studied using 3D digital image correlation (DIC) and neutron diffraction. The results showed that the martensite phase transformation was significantly influenced by deformation mode and strain path, with the most transformation occurring under biaxial tension and the least under plane strain deformation.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Materials Science, Multidisciplinary
Wei Tang, Chris M. Fancher, Peeyush Nandwana, Ke An, Andrzej Nycz, Hsin Wang, Rangasayee Kannan, Artem Trofimov, Dunji Yu, Donovan N. Leonard, Luke Meyer, Alex Plotkowski
Summary: Recent research has found that low transformation temperature (LTT) martensite steel can be used in wire arc additive manufacturing (WAAM) to produce printed walls with low tensile or compressive residual stresses. These residual stresses contribute to improved product properties. However, the thermal and mechanical properties of WAAM printed LTT martensite steel walls are not well understood.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2023)
Article
Engineering, Manufacturing
Ravi Sankar Haridas, Priyanka Agrawal, Saket Thapliyal, Priyanshi Agrawal, Abhijeet Dhal, Shivakant Shukla, Le Zhou, Yongho Sohn, Rajiv S. Mishra
Summary: This study investigates the tensile and high cycle fatigue behavior of a novel Al-Ni-Ti-Zr alloy with a heterogeneous microstructure. The alloy exhibits excellent strength-ductility synergy and fatigue performance, attributed to multiple crack retardation mechanisms and favorable crack propagation pathways. Additionally, a probabilistic model is used to estimate the fatigue life of the alloy based on the stochastic microstructure.
ADDITIVE MANUFACTURING
(2023)
Article
Chemistry, Multidisciplinary
Kun Lin, Wenbin Zhang, Chengyi Yu, Qiang Sun, Yili Cao, Wenjie Li, Suihe Jiang, Qiang Li, Qiang Zhang, Ke An, Yan Chen, Dunji Yu, Jue Liu, Kenichi Kato, Qinghua Zhang, Lin Gu, Xiaojun Kuang, Yu Tang, Jun Miao, Xianran Xing
Summary: Chemical heterogeneity, as a counterintuitive strategy, is proposed to design high-performance zero thermal expansion (ZTE) alloys. In a Hf-Ti-Fe alloy with excess Fe in the Hf/Ti sublattice, the introduction of chemical heterogeneity at the micro level regulates local magnetic interactions and triggers a dispersed magnetic phase transition, resulting in remarkable ZTE behavior. The strategy of local chemical heterogeneity opens up an avenue to design ZTE and related functional materials directly via microstructure engineering.
CELL REPORTS PHYSICAL SCIENCE
(2023)
Article
Materials Science, Multidisciplinary
W. Woo, Y. S. Kim, H. B. Chae, S. Y. Lee, J. S. Jeong, C. M. Lee, J. W. Won, Y. S. Na, T. Kawasaki, S. Harjo, K. An
Summary: In situ neutron diffraction experiments were conducted to investigate the behavior of cast-wrought (CW) and additively manufactured (AM) equiatomic CoCrNi medium-entropy alloys under loading. The study found that the dislocation density and stacking/twin fault probability increased significantly near fracture. The flow stress and strengthening mechanisms were also analyzed, showing the impact of dislocation slip and deformation twinning.
Article
Materials Science, Multidisciplinary
D. Xie, Z. H. Li, T. T. Sasaki, Y. F. Gao, Z. Y. Lyu, R. Feng, Y. Chen, K. An, H. B. Chew, T. Nakata, S. Kamado, K. Hono, P. K. Liaw
Summary: The low-alloyed Mg-Al-Ca-Mn alloy, as a new class of heat-treatable magnesium alloys, shows great engineering potential due to its excellent extrudability and high strength achieved by the dispersion of Guinier-Preston (G.P.) zones. In this study, in situ neutron diffraction measurements were conducted to investigate the cyclic deformation behavior of this alloy with and without G.P. zone dispersion. The relationship between macroscopic deformation behavior and microscopic response at the grain level, such as twinning and detwinning, was established.
Article
Materials Science, Multidisciplinary
Yanfang Liu, Jie Ren, Shuai Guan, Chenyang Li, Yin Zhang, Saideep Muskeri, Zhiyuan Liu, Dunji Yu, Yan Chen, Ke An, Yang Cao, Wei Liu, Yuntian Zhu, Wei Chen, Sundeep Mukherjee, Ting Zhu, Wen Chen
Summary: CoCrFeMnNi high-entropy alloys (HEAs) are additively manufactured using L-DED and L-PBF processes. Comparative studies reveal substantial differences in microstructures, crystallographic texture, and deformation mechanisms between L-DED and L-PBF samples. The L-DED samples exhibit a mixed crystallographic texture, larger solidification cell sizes, and enhanced plastic deformation capabilities, leading to higher ductility compared to the L-PBF samples. This work provides fundamental insights into the deformation mechanisms of additively manufactured HEAs and emphasizes the critical impact of processing conditions on solidification microstructure and material design by additive manufacturing.
Article
Multidisciplinary Sciences
Chengyi Yu, Kun Lin, Xin Chen, Suihe Jiang, Yili Cao, Wenjie Li, Liang Chen, Ke An, Yan Chen, Dunji Yu, Kenichi Kato, Qinghua Zhang, Lin Gu, Li You, Xiaojun Kuang, Hui Wu, Qiang Li, Jinxia Deng, Xianran Xing
Summary: The study presents a new type of ZTE alloy with wide operating temperature range, high strength-stiffness, and cyclic thermal stability. The alloy, constructed through boron-migration-mediated solid-state reaction, exhibits a superior dual-phase structure and provides a promising design paradigm for comprehensive performance ZTE alloys.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Abhijeet Dhal, Priyanka Agrawal, Ravi Sankar Haridas, Supreeth Gaddam, Aishani Sharma, Digvijay Parganiha, Rajiv S. Mishra, Hirotsugu Kawanaka, Shinji Matsushita, Yusuke Yasuda, Seung Hwan C. Park, Wei Yuan
Summary: This paper investigates the complex deformation mechanisms of Inconel 718 (IN718) superalloy processed by laser powder-bed fusion additive manufacturing (L-PBFAM) and heat treatment using high-resolution nanoindentation. The results reveal a crystal orientation dependency of modulus and hardness, as well as complex microscale strength variation due to thermal cycles. The heat treatment activates multiple precipitation-strengthening mechanisms, leading to a significant increase in yield strength. The orientation-dependent hardness distribution is contributed by the high mechanical anisotropy and coherency strengthening of precipitates.
Article
Computer Science, Artificial Intelligence
S. V. Venkatakrishnan, Chris M. Fancher, Maxim Ziatdinov, Rama Vasudevan, Kyle Saleeby, James Haley, Dunji Yu, Ke An, Alex Plotkowski
Summary: Neutron diffraction is a useful technique for mapping residual strains in dense metal objects. In this paper, the authors propose an object adaptive sampling strategy to measure the significant points first and predict the next most informative positions to measure. They demonstrate the real-time measure-infer-predict workflow on additively manufactured steel parts, leading to faster strain mapping with useful real-time feedback.
MACHINE LEARNING-SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Mechanical
Weicheng Zhong, Sho Hayakawa, Haixuan Xu, Ke An, Albina Y. Borisevich, Joshua L. Cicotte, Easo P. George, Ying Yang
Summary: In this study, a face-centered cubic (fcc) Fe-Cr-Co-Ni medium-entropy alloy was designed and tensile tested. Multiple deformation mechanisms were triggered through control of the relative stabilities of different phases in this alloy, resulting in sustained work hardening. The alloy showed extensive deformation-induced nanotwinning at room temperature and a two-step sequential phase transformation at 77K, providing new templates for the design of alloys with multiple deformation mechanisms.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Multidisciplinary Sciences
A. Plotkowski, K. Saleeby, C. M. Fancher, J. Haley, G. Madireddy, K. An, R. Kannan, T. Feldhausen, Y. Lee, D. Yu, C. Leach, J. Vaughan, S. S. Babu
Summary: Residual stresses impact the performance and reliability of manufactured goods and are commonly found in casting, welding, and additive manufacturing. By utilizing operando neutron diffraction, the authors investigate the lattice strain evolution during the printing of a low-temperature transformation steel, providing insights into the mechanisms involved and enabling the design of residual stress states and property distributions in additively manufactured components.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Dawei Zhang, Yan Chen, Heidy Vega, Tianshi Feng, Dunji Yu, Michelle Everett, Joerg Neuefeind, Ke An, Renkun Chen, Jian Luo
Summary: Neutron diffraction and total scattering techniques were used to investigate a series of single-phase 10-component compositionally complex fluorite-based oxides (10CCFBOxNb). It was found that a long-range order-disorder transition occurred at x = 0.81 ± 0.01. Rietveld refinements of neutron diffraction patterns suggested that this transition was caused by the migration of oxygen anions. In addition, diffuse scattering was observed in Nb-rich compositions, indicating the presence of short-range order.
ADVANCED POWDER MATERIALS
(2023)
