纳米晶体镍片剪切带演化的实验研究

Experimental Study on Evolution Behavior of Shear Bands in Nanocrystalline Ni Sheets

摘要:

以高纯度、高致密度的纳晶金属镍片为研究对象，利用数字图像相关方法研究了其在单轴准静态拉伸载荷下的剪切带化变形行为，系统分析了纳晶金属镍片中剪切带的萌生及演化规律，定量分析了剪切带形核、扩展和失效的重要节点，讨论了纳晶镍剪切带的物理特征。结果显示：剪切带的演化发展是纳晶镍试样塑性变形的主要形式，是纳晶镍试样具有较低延性的原因

Abstract:

A quantitative experimental study with digital image correlation (DIC) algorithm on shear banding deformation behaviors of high purity, fully dense nanocrystalline Ni sheet subjected to quasi-static uniaxial tensile load was carried out. Based on that, onset and evolution of shear bands in nanocrystalline Ni were analyzed, and some critical points, such as shear band nucleation, broadening process and failure point were recognized quantitatively. Finally, the physical characteristics of shear bands, such as inclination and width, were discussed. Results show that the nanocrystalline Ni exhibits shear localization in the form of shear band, which is the main reason of the early failure during plastic deformation