利用X射线衍射仪(XRD),高分辨透射电镜(HRTEM)对Zr65Al7.5 Ni10Cu12.5Ag5非晶合金Vickers压痕的微观结构变化进行了研究,在压头棱下方和压头尖端下方区域分别观察到了微米和纳米尺寸的晶粒析出.结合有限元模拟,分析了压应力对晶化过程中形核及晶核长大的影响,在压应力最大的尖端区域形核激活能最小,形核速率最大,需要的晶核长大激活能也最大.压应力越小形核速率越小,需要的晶核长大激活能越小.应力是影响非晶合金在塑性变形过程中发生晶化的动力学因素之一.%X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) were applied to investigate the microstructurc changing during the Vickers indentation of the Zr65Al7.5, Ni10Cu2.0,Ag5, amorphous alloy. The results showed thar the micro-sized crystals precipitated under the indentcr edges and nano-sized crystals form under the indenter tip. The nucleation behaviors induced by indentation was investigated with help of the finite element simulation in the deformed regions. On the tip region with larger compressive stresses, the nucleation activation energy becomes much lower while the nucleation rate becomes considerably larger. The results show that the compressive stress is one of the most important factors influencing on the crystallization kinetics of an amorphous alloy during plastic deformation.
展开▼
