共 50 条
Stress-induced failure transition in metallic glasses
被引:0
|作者:
Meng, Lingyi
[1
]
Zhang, Yuxin
[1
]
Tang, Xiaochang
[1
]
Yao, Xiaohu
[2
]
机构:
[1] South China Univ Technol, Sch Civil Engn & Transportat, Dept Engn Mech, Guangzhou 510640, Peoples R China
[2] South China Univ Technol, State Key Lab Subtrop Bldg Sci, Guangzhou 510640, Peoples R China
基金:
中国博士后科学基金;
中国国家自然科学基金;
关键词:
Metallic glass;
Shear band;
MICRO-void;
Failure transition;
Stress triaxiality;
Structural origin;
CONSTITUTIVE MODEL;
BRITTLE;
PLASTICITY;
FRACTURE;
D O I:
10.1016/j.ijplas.2024.104152
中图分类号:
TH [机械、仪表工业];
学科分类号:
0802 ;
摘要:
As a novel and highly promising metal in the future application of weapons equipment and aerospace fields, metallic glasses (MGs) demonstrate intricate failure modes that encompass both the brittle and plastic characteristics when subjected to varying loading conditions. In this work, a set of Cu50Zr50 models subjected to a combined pure shear and equi-triaxial tension loading are simulated via molecular dynamics to investigate the impact of the stress state on the complex failure modes of MGs. The characteristic and critical moments when failure occurs are established under both the shear-band-induced shear failure and the micro-void-induced tensile fracture. The stress triaxiality is applied as a pivotal stress parameter that governs the transition from the shear failure mode to the tensile failure mode. The critical stress triaxiality of Cu50Zr50 MG is approximately in the range of (2.0, 3.0) when both the shear and tension failures simultaneously occur, resulting in the largest failure strain at various stress states. We subsequently obtain a nearly elliptical yield surface of the Cu50Zr50 MGs, in which the shear failure zone, tensile failure zone, and transition zone are clearly distinguished. The microstructural evolution of MGs during the failure transition is analyzed from the perspective of the specific short-range order. In contrast to the tensile deformation, icosahedral (quasi-icosahedral) clusters demonstrate a high level of shear resistance and remain stable in the shear-dominant deformations, which is confirmed as the structural origin of the stress state impacting the failure transition.
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页数:15
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