共 12 条
Effect of loading rate on creep behavior and shear transformation zone in amorphous alloy thin films, and its correlation with deformation mode transition
被引:10
|作者:
Cao, Q. P.
[1
]
Sun, L. J.
[1
]
Wang, C.
[1
]
Fu, Y.
[1
]
Liu, S. Y.
[1
]
Qu, S. X.
[2
]
Wang, X. D.
[1
]
Zhang, D. X.
[3
]
Jiang, J. Z.
[1
]
机构:
[1] Zhejiang Univ, Sch Mat Sci & Engn, ICNSM, Hangzhou 310027, Zhejiang, Peoples R China
[2] Zhejiang Univ, Inst Appl Mech, Hangzhou 310027, Zhejiang, Peoples R China
[3] Zhejiang Univ, State Key Lab Modern Opt Instrumentat, Hangzhou 310027, Zhejiang, Peoples R China
来源:
基金:
中国国家自然科学基金;
关键词:
Amorphous alloy thin films;
Nanoindentation;
Strain rate;
Shear transformation zone;
Deformation mode transition;
METALLIC GLASSES;
HOMOGENEOUS FLOW;
PLASTIC-FLOW;
INHOMOGENEOUS FLOW;
SERRATED FLOW;
NANOINDENTATION;
TEMPERATURE;
SIZE;
DEPENDENCE;
PD;
D O I:
10.1016/j.tsf.2019.04.050
中图分类号:
T [工业技术];
学科分类号:
08 ;
摘要:
The effects of loading rate on creep behavior and shear transformation zone (STZ) in magnetron sputtered La-Co-Al and Zr-Cu-Ni-Al amorphous alloy thin films were characterized through instrumented nanoindentation with a spherical indenter. It was revealed that with an increase in loading rate, both thin films became harder with a narrower distribution of mechanical response, and exhibited more pronounced creep displacement with higher creep strain rate. Based on cooperative shear model, both STZ volume and activation energy were calculated by measuring the strain rate sensitivity during creep, showing an increasing tendency with loading rate. However, the strain rate sensitivity was found to decrease with loading rate. Furthermore, structural heterogeneity density, estimated by analyzing the stressed volume at yielding, decreased with loading rate. Therefore, with increasing loading rate, the STZ event can only be activated at detectable structural heterogeneities with relatively larger volume, and the number of available fertile sites was decreased, resulting in postponed shear band formation and suppressed deformation mode transition.
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页码:23 / 31
页数:9
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