Article
Nanoscience & Nanotechnology
Zhanfeng Wang, Junjie Zhang, Jinzhong Lu
Summary: This study investigates the deformation mechanisms of single crystal and bicrystal Cu workpieces under nanoindentation through experiments and molecular dynamics simulations. The results highlight the significant role of dislocation-grain boundary interactions and crystallographic orientation on the mechanical response of the materials.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Siyao Shuang, Songjiang Lu, Bo Zhang, Chen Bao, Qianhua Kan, Guozheng Kang, Xu Zhang
Summary: Molecular dynamics simulations were used to study the elastic-plastic behavior of high-entropy alloys, revealing that load-drop phenomenon during indentation in HEAs is less obvious compared to traditional metals, and a dense dislocation network forms underneath the indenter. Twin boundaries inhibit dislocation penetration and provide slipping paths for dislocations.
COMPUTATIONAL MATERIALS SCIENCE
(2021)
Article
Materials Science, Multidisciplinary
Zhipeng Li, Jianfei Zhang, Yadi Zhai, Jiabao Zhang, Xiaodong Wang, Ze Zhang, Shengcheng Mao, Xiaodong Han
Summary: In-situ TEM nanoindentation reveals the characteristics of dislocation pinning, pile-ups and cross-slip along the twinning boundary in a twinned FCC metal for the first time.
MATERIALS RESEARCH LETTERS
(2022)
Article
Multidisciplinary Sciences
Vahid Samaee, Maxime Dupraz, Thomas Pardoen, Helena Van Swygenhoven, Dominique Schryvers, Hosni Idrissi
Summary: In-situ transmission electron microscopy observations in nickel bi-crystal samples provide insights into the formation of constriction nodes at coherent twin boundaries (CTBs) by the absorption of curved screw dislocations, leading to a unique CTB sliding mechanism involving coordinated twinning dislocation pairs. The interactions between non-screw dislocations and CTBs highlight the importance of the synergy between the repulsive force of CTBs and the back stress from single arm dislocation sources (SASs) in small volumes. The findings contribute to the understanding of the mechanisms controlling the strength and ductility of metals at coherent twin boundaries.
NATURE COMMUNICATIONS
(2021)
Article
Materials Science, Multidisciplinary
Qin Zhang, Bingrao Zhou, Yimin Wang, Zefei Zhang, Zhiwei Zang, Zhiqing Lv
Summary: This study simulated nanoindentation experiments on a (110) crystal plane with a spherical indenter and (111) twin boundaries at different distances using molecular dynamics. It calculated the load-displacement curves and mechanical properties, and analyzed the deformation mechanism of the nickel matrix using a dislocation extraction algorithm. The results showed that the load decreased in the load-displacement curve due to the nucleation of dislocations, and the twinning boundary hindered dislocation propagation. Young's modulus values near the twin boundary were lower than those farther away, and the maximum shear stress near the twin boundary was lower.
MATERIALS SCIENCE AND TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Reza Hosseinabadi, Heinz Riesch-Oppermann, James P. Best, Gerhard Dehm, Christoph Kirchlechner
Summary: The impact of a coherent twin boundary (CTB) on the size scaling of shear stress in micropillar compression tests has been investigated. The study found that the CTB has a size-dependent contribution to shear stress, with a more prominent effect observed in smaller pillars.
Article
Crystallography
Longlong Yang, Kun Sun, Weixiang Peng, Xuejie Li, Liang Zhang
Summary: This study investigates the effect of grain boundary angles on the initial deformation of nitrogen-containing 0Cr19Ni10 austenitic stainless steel using molecular dynamics simulations. The results show that grain boundary angles have significant effects on the mechanical properties of the material, providing insights into the angle effects of grain boundaries in materials.
Article
Nanoscience & Nanotechnology
Linfeng Bu, Zhao Cheng, Yin Zhang, HengAn Wu, Ting Zhu, Lei Lu
Summary: The strength-controlling dislocation mechanism in nanotwinned metals is illuminated by partitioning the flow stress into effective stress and back stress components. Recent experiments show a nearly constant saturated effective stress of about 100 MPa in nanotwinned Cu with nanotwin thicknesses less than 100 nm. This surprising result suggests that trans-twin dislocations spanning multiple nanotwin lamellae, rather than threading dislocations within individual lamellae, control the effective stress.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
Yongzhi Xi, Xiaofeng Yang, Xunlu Yin, Xinxin Liu, Xiancheng Zhang, Hao Chen
Summary: The interactive strengthening effect of twin boundary and local chemical ordering (LCO) structure was investigated in CoCrNi medium-entropy alloy (MEA). The results showed that both LCO and twin boundary enhance the hardness of the alloy. When LCO and twin boundary are coupled, a concurrent strengthening effect occurs, significantly improving the hardness. The twin boundary provides a slipping path for dislocations, while the LCO structure limits the slip of dislocations on the twin boundary.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Jing Tang, Chuanlong Xu, Zikun Li, Xiaobao Tian, Wentao Jiang, Qingyuan Wang, Haidong Fan
Summary: The interaction between a {10 (1) over bar2} twin boundary and irradiation-induced < c > dislocation loops in magnesium at room temperature was studied using molecular dynamics simulations. The results showed that the twin boundary can always transform the dislocation loops into glissile < a > dislocation loops, regardless of the partial Burgers vectors. This work provides new insights into understanding the irradiation effects in magnesium and other hexagonal close-packed metals.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Engineering, Mechanical
Dongpeng Hua, Qiaosheng Xia, Wan Wang, Qing Zhou, Shuo Li, Dan Qian, Junqin Shi, Haifeng Wang
Summary: Understanding contact-induced behavior in metals is crucial for studying mechanical properties. Nanoindentation studies on CoCrNi MEA revealed unique dislocation nucleation at Cr-rich clusters, contrary to conventional homogeneous nucleation in pure metals. Compositional inhomogeneity and temperature were found to influence defect behavior, with nanotwin formation and phase-transformation promoted at low temperatures.
INTERNATIONAL JOURNAL OF PLASTICITY
(2021)
Article
Materials Science, Multidisciplinary
Yue Gao, Tinghong Gao, Lianxin Li, Quan Xie, Qian Chen, Zean Tian, Yongchao Liang, Bei Wang
Summary: This study used molecular dynamics to investigate the formation mechanism of dislocation and twin structures in Ti3Al during rapid solidification. Two microstructure types were obtained: nanocrystalline, composed of multiple grains, and lamellar structure dominated by stacking fault and coherent twin boundary. The analysis of crystal defects formation and evolution under different models provides a reference for understanding the mechanical properties of Ti3Al alloys with various microstructures.
Article
Materials Science, Multidisciplinary
Huhu Su, Xinzhe Zhou, Shijian Zheng, Hengqiang Ye, Zhiqing Yang
Summary: The study investigated the reactions between basal dislocations and CTBs in a Mg alloy, showing that these reactions can facilitate TB migration and change the grain boundary structure. The loss of local coherency induced by dislocation-TB reactions does not inherently impede TB migration, providing a new strategy to improve the ductility of Mg alloys.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2021)
Article
Materials Science, Multidisciplinary
Dinh-Quan Doan
Summary: The influence of crystal orientation and twinning on the mechanical properties and microstructure development of equiatomic FeNiCrCoCu high-entropy alloy was investigated using nanoindentation and molecular dynamics. The study found that crystal orientation affects substrate hardness and loading curves, while decreasing twin boundary distance enhances material strength and ductility. Additionally, the evolution of microstructure is influenced by interaction between sliding system and twinning, with various surface morphologies dominated by sliding mechanism along primary sliding system.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Nanoscience & Nanotechnology
Y. Yue, J. F. Nie
Summary: The interaction between a matrix prismatic < c > edge dislocation and a migrating (10 <(1)over bar > 2) twin boundary is studied. The resulting < a > dislocation tends to detach from or connect to the twin boundary, depending on its slip plane intersection with the compression or extension site of the twin boundary. When connected, the < a > dislocation forms a 90 Shockley partial with a basal-prismatic (BP) or prismatic-basal (PB) two-atomic-layer-height step.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Zhenquan Yang, Aibin Ma, Bingqian Xu, Jinghua Jiang, Jiapeng Sun
Summary: The microstructure of a commercial AZ91 Mg alloy was modified through ECAP and aging, resulting in improved corrosion resistance. Aging treatment at 150 degrees Celsius for 60-90 hours produced fine beta phase precipitates that enhanced the micro-galvanic effect, leading to increased corrosion rates still lower than that of the as-cast alloy.
Article
Materials Science, Multidisciplinary
Bingqian Xu, Jiapeng Sun, Jing Han, Zhenquan Yang, Hao Zhou, Lirong Xiao, Songsong Xu, Ying Han, Aibin Ma, Guosong Wu
Summary: Hierarchical precipitates composed of various phases in a fine-grain magnesium-gadolinium-silver alloy obtained through ECAP and subsequent peak-aging process facilitate corrosion to some extent, but their spatial redistribution improves the material's corrosion resistance possibly due to the formation of a protective corrosion product film.
Article
Nanoscience & Nanotechnology
Zhenquan Yang, Aibin Ma, Bingqian Xu, Jinghua Jiang, Haoran Wu, Jiapeng Sun
Summary: The novel stepless-temperature-reduction ECAP approach demonstrates advantages in microstructure refining and texture modifying of Mg-Al alloys, resulting in ultrafine grain structure and high tensile yield strength.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Lian Hua, Jiapeng Sun, Guosong Wu
Summary: A facile strategy is proposed in this study to control the corrosion behavior of hydrothermally-treated magnesium-aluminum alloys, and aging treatment is attempted to modify their metallurgical microstructure. After hydrothermal treatment, both the unaged and the aged alloy have a layer of dense coating, but the aged alloy shows better corrosion resistance.
Article
Materials Science, Multidisciplinary
Jianqing Chen, Yehan Su, Qiyu Zhang, Jiapeng Sun, Donghui Yang, Jinghua Jiang, Dan Song, Aibin Ma
Summary: A homogeneously ultrafine-grained (UFG) Cu-38 Zn alloy with an average grain size of 0.64 μm was successfully fabricated by equal channel angular processing (ECAP), exhibiting a significantly enhanced strength-ductility synergy. The observed strength enhancement can be attributed to grain refinement and dislocation strengthening. After annealing, the alloy showed further improved strength with almost unchanged ductility, which is associated with solute/impurity segregation and precipitation phenomena inside the grains.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Jing Han, Cong Wang, Yuanming Song, Zhiyuan Liu, Jiapeng Sun, Jiyun Zhao
Summary: The ultrasonic surface rolling (USR) technique has been used to improve the corrosion resistance and mechanical properties of Mg alloy casting parts. The USR sheet exhibits significant enhancements in strength, hardness, and corrosion resistance without sacrificing ductility. This method can be considered as an additional and last working procedure in the production of high-performance Mg alloy casting parts.
INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Xinran Yao, Yujie Yang, Minxing Zheng, Jinghong Wang, Changyang Liu, Jiapeng Sun, Guosong Wu
Summary: This study proposes a strategy to enhance the corrosion resistance of magnesium alloys by transforming corrosion products into protective coatings. By immersing a magnesium-neodymium alloy in potassium dihydrogen phosphate solution, a uniform MgHPO4·3H2O coating is formed, which significantly improves the corrosion resistance of the alloy.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Bangjun Li, Jiapeng Sun, Bingqian Xu, Guosong Wu
Summary: This paper investigates the corrosion behavior of Mg-5.7Gd-1.9Ag alloy sheets in a salt solution. The results show that the rolled sheets exhibit better corrosion resistance compared to the as-cast sheets. Aging treatment decreases corrosion resistance, but it still remains higher than that of the as-cast sheets. The migration of corrosion is mainly influenced by the evolution of second phases rather than grain size and texture.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Mingkun Jiang, Ying Han, Jiapeng Sun, Guoqing Zu, Weiwei Zhu, Yu Zhao, Hua Chen, Xu Ran
Summary: In this study, different microscopic techniques were used to characterize the precipitation behavior of the Cu-rich phase in Al-free and Al-containing ferrite stainless steels. The effects of Al addition on the precipitation and coarsening of the Cu-rich phase were analyzed. The results showed that Al increased the nucleation rate of the Cu-rich phase and refined the Cu-rich nanoprecipitates. The crystal structures of the Cu-rich phase changed after Al addition. The Al-containing Cu-rich phase had high-density edge dislocations, which acted as diffusion channels and increased the coarsening rate of the Cu-rich phase. However, with the extension of the aging time, the dislocation density in the Al-containing Cu-rich phase decreased, weakening the promotion effect of Al on the coarsening of the Cu-rich phase.
MATERIALS & DESIGN
(2022)
Article
Chemistry, Physical
Qisheng Sun, Jiapeng Sun, Yantao Fu, Bingqian Xu, Ying Han, Jianqing Chen, Jing Han, Hao Wu, Guosong Wu
Summary: In this study, a thick GS surface layer with a thickness of 1.1 mm was successfully produced in Cu-38 wt.% Zn alloy using ultrasonic severe surface rolling technology. The results show that the volume fraction of the GS surface layer can be tailored to achieve a balance between strength and ductility in the alloy.
Article
Materials Science, Multidisciplinary
Jiapeng Sun, Qisheng Sun, Ying Liu, Bangjun Li, Zheng Zhang, Bingqian Xu, Songsong Xu, Ying Han, Yanxin Qiao, Jing Han, Guosong Wu, Paul K. Chu
Summary: The study investigates the use of ultrasonic severe surface rolling (USSR) to enhance the corrosion resistance of SLM 316L stainless steel, and finds that the USSR processed samples exhibit significant improvement in corrosion resistance, attributed to the unique gradient structure and chemically homogeneous and high-quality surface.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Materials Science, Multidisciplinary
Changyang Liu, Jiapeng Sun, Guosong Wu
Summary: A simple solution-immersion method based on the concept of predesigned corrosion is developed to enhance the corrosion resistance of a magnesium-neodymium alloy, providing a feasible way to prepare a superhydrophobic surface on the alloy. The superhydrophobic surface exhibits self-cleaning behavior and good corrosion resistance in artificial hand sweat, offering new technical insights into the corrosion protection of magnesium alloys.
Article
Materials Science, Multidisciplinary
Qisheng Sun, Jiapeng Sun, Jing Han, Guosong Wu
Summary: Designing a gradient nanostructure is an effective strategy to strengthen commercial pure Ti without sacrificing ductility. This study investigates the corrosion behavior of GNS pure Ti in hydrochloric acid and finds that GNS pure Ti exhibits enhanced corrosion resistance and passivation ability due to high-density grain boundaries, dislocations, and a smooth surface.
Article
Materials Science, Multidisciplinary
Jiapeng Sun, Bingqian Xu, Zhenquan Yang, Feihu Jiang, Keke Yang, Jing Han, Guosong Wu
Summary: A hierarchal micro-nano beta phase framework is proposed to improve the barrier effect of the second phase in high-aluminum-containing Mg-Al alloy, which effectively mitigates corrosion due to the formation of a brick-and-mortar structured corrosion product layer.
Article
Materials Science, Multidisciplinary
Bangjun Li, Jiapeng Sun, An Xu, Bingqian Xu, Lingling Wang, Jie Yuan, Guosong Wu
Summary: It is still challenging to simultaneously improve the mechanical properties and corrosion resistance of Mg alloys through one strategy. In this paper, high-density nanoprecipitates are introduced in a Mg alloy to enhance its strength and corrosion resistance.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
