Article
Nanoscience & Nanotechnology
H. Zhang, Z. Wang, H. J. Yang, X. H. Shi, P. K. Liaw, J. W. Qiao
Summary: Based on microscopic mechanisms, a constitutive equation for crack-like propagation velocity and a flow model for bulk metallic glasses (BMGs) are derived. The model explains the fundamental deformation of BMGs and accurately predicts the transition between serrated and non-serrated flows. The results are consistent with experimental data, providing a theoretical basis for plastically processing BMGs.
SCRIPTA MATERIALIA
(2023)
Article
Nanoscience & Nanotechnology
Yonghui Mo, Xiaochang Tang, Lingyi Meng, Junwei Qiao, Xiaohu Yao
Summary: Shear band behavior is crucial in toughening and failure of bulk metallic glasses (BMGs). This study investigates the spatial-temporal evolutions of shear bands in BMGs using DIC and ITI technologies. The experimental results are in agreement with the simulation results in some respects, providing insights for prediction of primary shear band, prevention of failure, and toughening method in BMGs.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Mechanical
Wei Rao, Yan Chen, Lan-Hong Dai
Summary: We have developed a new constitutive model for metallic glass that considers its out-of-equilibrium characteristics. By dividing the total internal energy into configurational and kinetic subsystems, and introducing configurational temperature coupling, we can effectively predict the deformations and shear banding behavior of metallic glasses.
INTERNATIONAL JOURNAL OF PLASTICITY
(2022)
Article
Chemistry, Physical
Mohammad Taghi, Asadi Khanouki
Summary: This paper investigates the temperature rise in shear bands and its effect on crystallization behavior in bulk metallic glasses. The temperature profile inside and around shear bands is determined by the released elastic energy, shear band thickness, and energy transfer time. The size of the hot zone is found to be equal to the stable crack growth region, while the size of the liquid zone is equal to the vein pattern size on the fracture surface. Crystallization occurs around hot shear bands and inside cold shear bands, but only on the compressive side of the specimen. These findings provide valuable insights into the deformation behavior of bulk metallic glasses using an analytical approach.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Nanoscience & Nanotechnology
Yonghui Mo, Lingyi Meng, Xiaohu Yao
Summary: Shear banding behavior is significant in the deformation and failure mechanisms of metallic glasses. This study reveals the spatial-temporal evolutions of shear bands and their correlation with principal shear stress using digital image correlation technologies.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Xiaojun Sun, Jie He, Dunbo Yu, Yang Luo, Zilong Wang, Yuanfei Yang
Summary: This work investigates the relationship between structural heterogeneity and serrated flow in nanoscale phase separated Zr-Cu-Fe-Al bulk metallic glasses with different plasticity. The results show that as the atomic ratio of Cu to Fe increases, serration dynamics transform from a chaotic state to a self-organized critical state. This transformation is attributed to the increase in structural heterogeneity, which promotes the formation of multiple shear bands.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Y. S. Luo, J. J. Li, Z. Wang, M. Zhang, J. W. Qiao
Summary: Based on a simple mean-field model, two distinct types of slip avalanches in serrated plastic flows of bulk metallic glasses were identified to differentiate the slipping modes of shear bands under various strain rates. Small avalanches propagate progressively, while large avalanches follow a simultaneous propagation. By defining a weakening parameter and critical size, researchers were able to characterize the completely disparate shearing modes, with larger weakening and lower critical sizes indicating more activated shear transformation zones, offering a new method to explore plasticity in bulk metallic glasses.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Jian Luo, Liping Huang, Yunfeng Shi, Binghui Deng
Summary: We conducted molecular dynamics simulations on metallic glasses to investigate the dynamics of shear band propagation. Our findings reveal that shear bands in metallic glasses exhibit supersonic propagation speed, microbranching, and velocity fluctuations, indicating intrinsic instability. The intersection of two shear bands under tension also leads to path deflection, speed slowing-down, and temperature rise at the junction region. These results suggest that shear bands in metallic glasses can be viewed as shear cracks in weakly nonlinear fracture mechanics theory.
Article
Nanoscience & Nanotechnology
C. Liu, Y. Ikeda, R. Maass
Summary: This study provides strong evidence for the accumulation of structural damage in Zr-based bulk metallic glass as a result of shear strain admitted by shear bands. Analysis of shear-band structure with high-angle annular dark field transmission electron microscopy reveals scattered data with an overall trend of increasing local volume dilatation with increasing shear strain. However, locally, a variety of trends are observed, highlighting the strong heterogeneity of structural damage in shear bands in metallic glasses.
SCRIPTA MATERIALIA
(2021)
Article
Metallurgy & Metallurgical Engineering
Hong Wu, Feng Xu, Jun-ye Ren, Xiao-dong Lan, Yong Yin, Lu-xin Liang, Min Song, Yong Liu, Jia Li, Qing-xiang Li, Wei-dong Huang
Summary: The study investigates the creep behavior of BMG at different loading rates, revealing that at low loading rates, serrated flow occurs while at high loading rates, homogeneous flow is observed. The rate-dependent creep behavior is attributed to the number of pre-existing major shear bands significantly influenced by the loading rate.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
Article
Chemistry, Physical
Hongbo Zhou, Laiquan Shen, Baoan Sun, Weihua Wang
Summary: Metallic glasses have unique mechanical properties due to their disordered structure. Understanding the atomic mechanisms of shear banding behavior is important for improving their mechanical properties. This review provides an overview of shear band nucleation, propagation, and interaction, as well as the dynamics and properties of mature shear bands. The fracture mechanism based on cavity development is also discussed, and key unsolved issues in this field are identified.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Review
Materials Science, Multidisciplinary
Cheng Zhang, Di Ouyang, Simon Pauly, Lin Liu
Summary: Bulk metallic glasses (BMGs) as metallic materials without long-range order have attracted significant attention from academia and industry in the past three decades. The emerging 3D printing technology provides a viable route to overcome the challenges inherent in conventional processing routes and expand the applications of BMGs.
MATERIALS SCIENCE & ENGINEERING R-REPORTS
(2021)
Article
Multidisciplinary Sciences
Florian Spieckermann, Daniel Sopu, Viktor Soprunyuk, Michael B. Kerber, Jozef Bednarcik, Alexander Schokel, Amir Rezvan, Sergey Ketov, Baran Sarac, Erhard Schafler, Juergen Eckert
Summary: In-situ X-ray diffraction is used to study structural rearrangements during annealing processes in Cu44Zr-44Al8Hf2Co2 bulk metallic glass. The deformation-induced rejuvenation reveals a structural footprint that can be correlated to calorimetric signals, showing characteristics of a first-order transition for the beta-transition. Dynamic mechanical analysis data indicates that non-reversible structural rearrangements are preferentially activated during the beta-transition, while reversible deformations dominate the low-temperature alpha-transition with second-order characteristics.
NATURE COMMUNICATIONS
(2022)
Review
Chemistry, Physical
D. Sopu
Summary: The complex nature of shear banding and the disordered structure of metallic glasses pose challenges in understanding the mechanisms of strain localization and shear band formation. The percolation of shear transformation zones (STZs) is widely accepted as the atomic-scale mechanism for shear banding. This review provides an up-to-date assessment of the STZ-Vortex mechanism and its applications in understanding shear band dynamics and deformation mechanisms in metallic glasses. It also highlights unresolved issues where the STZ-Vortex model could be effectively applied.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Daniel Sopu, Florian Spieckermann, Xilei Bian, Simon Fellner, Jonathan Wright, Megan Cordill, Christoph Gammer, Gang Wang, Mihai Stoica, Juergen Eckert
Summary: Residual stress engineering is important for the design of advanced lightweight materials. In this study, the effects of stress and structure modulation on metallic glasses were investigated using various techniques, such as high-energy scanning X-ray diffraction and microindentation hardness mapping. The results show that simultaneous stress and structural modulation can enhance the ductility and strain-hardening ability of metallic glasses.
NPG ASIA MATERIALS
(2023)
Article
Physics, Applied
Ming Zhao, Mo Li
APPLIED PHYSICS LETTERS
(2008)
Article
Materials Science, Multidisciplinary
Ming Zhao, Mo Li, Yu-Feng Zheng
PHILOSOPHICAL MAGAZINE LETTERS
(2011)
Article
Nanoscience & Nanotechnology
Ming Zhao, Mo Li
SCRIPTA MATERIALIA
(2011)
Article
Materials Science, Multidisciplinary
Ming Zhao, Mo Li
Article
Materials Science, Multidisciplinary
Zhenquan Shen, Ming Zhao, Dong Bian, Danni Shen, Xiaochen Zhou, Jianing Liu, Yang Liu, Hui Guo, Yufeng Zheng
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2019)
Article
Materials Science, Multidisciplinary
Xiao-Chen Zhou, Fan Yang, Xiao-Yan Gong, Ming Zhao, Yu-Feng Zheng, Zhi-Li Sun