不同成分金属玻璃薄膜在纳米压入与划痕中的力学响应

Mechanical response of metallic glass thin films with different components during nanoindentation and nanoscratch

本文通过纳米压痕及划痕测试探究了不同成分金属玻璃薄膜在纳米尺度的力学响应行为.系统地研究了具有不同脆性指数的Cu_(50)Zr_(50), Ni_(62)Nb_(38), Fe_(70)Nb_(10)B_(20)和Co_(56)Ta_(35)B_(9)四种金属玻璃薄膜在不同加载速率条件下的纳米压入锯齿流变行为.结合理论计算分析了不同加载条件下金属玻璃薄膜的蠕变行为,获得了材料内部剪切转变区体积.通过纳米划痕实验探究了不同成分的金属玻璃薄膜的耐磨性.结果表明金属玻璃薄膜的流变方式依赖于加载速率的变化.剪切转变区体积大小是由玻璃的脆性指数和弛豫态结构与加载速率的共同作用所致,玻璃内部不均匀程度越大剪切转变区体积越容易受加载速率的影响.

In this paper, the nanoscale mechanical response of metallic glass thin films with different components is studied via the nanoindentation and nanoscratch tests. The serrated flow behaviors of Cu50Zr50, Ni62Nb38, Fe70Nb10B20, and Co56Ta35B9metallic glass thin films with different fragilities under various nanoindentation loading rates were systematically studied. The nanoindentation creep behaviors of metallic glass films under different loading conditions were analyzed;the volume of the shear transition zone in each material was calculated. The wear resistance of metallic glass thin films with different components was studied via the nanoscratch experiment. The results show that the serrated mode of a metallic glass film depends on the change in the loading rate. The volume of the internal shear transition zone in a metallic glass film depends on the fragility and the joint effect of the substrate temperature and loading rate. Generally,the larger the degree of material heterogeneity, the more easily the volume of the shear transition zone is affected by the loading rate. Combined with the nanoscratch experiment, the wear resistance of metallic glass film was primarily dependent on its hardness.