Effects of pores on shear bands in metallic glasses: A molecular dynamics study
Effects of pores on shear bands in metallic glasses: A molecular dynamics study
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DOI：
10.1016/j.commatsci.2010.08.001
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发表时间：
2010-11
影响因子：
3.3
通讯作者：
Jiangting Wang;P. Hodgson;Jingde Zhang;Wenyi Yan;Chunhui Yang
中科院分区：
文献类型：
--
作者：
Jiangting Wang;P. Hodgson;Jingde Zhang;Wenyi Yan;Chunhui Yang
采用分子动力学（MD）模拟研究了纳米压痕和单轴压缩实验中纳米孔对多孔Cu46Zr54金属玻璃强度和塑性的影响。在分子动力学模拟中，采用快速淬火的方法从液态铜和锆合金中制备了原子级非晶样品。在纳米压痕和单轴压缩模拟中，通过样品中的局部偏剪应变观察到剪切转变区和剪切带。结果表明，孔隙的存在引起应变集中，极大地促进了剪切带的初始化和扩展。重要的是，只有达到临界尺寸的孔隙才能有效地促进多个剪切带的形成。还观察到，硬化发生通过孔隙湮灭和剪切带停止在多孔金属玻璃。
The effects of nanoscale pores on the strength and ductility of porous Cu46Zr54metallic glasses during nanoindentation and uniaxial compression tests are modelled and investigated using molecular dynamics (MD) simulations. In the MD simulations, atomistic amorphous samples were digitally prepared through fast quenching from the liquid states of copper and zirconium alloy. In both of the nanoindentation and uniaxial compression simulations, shear transformation zones and shear bands are observed through the local deviatoric shear strains in the samples. The results show that the existence of pores causes strain concentrations and greatly promotes the initialization and propagation of shear bands. Importantly, only pores reaching critical size can effectively facilitate the formation of multiple shear bands. It is also observed that hardening occurs through pore annihilation and the shear band stops in porous metallic glasses.