多晶体钛拉伸变形表面褶皱的形成及晶粒变形

用原子力显微镜对多晶体钛拉伸塑性变形中表面褶皱的形成及单个晶粒的变形进行了连续观察和测量.结果表明,表面褶皱随着应变量的增加而增大,而凹凸的相对位置关系不随变形的进行而变化.从单个晶粒来看应变量在0.1附近时由于孪晶的形成产生了新的凹凸,但对整体的表面褶皱凹凸位置关系没有大的影响.表面平均粗糙度和表面最大高低差随应变量的增加近似呈直线性增大,应变量在0.1左右时由于孪晶的形成,使粗糙度有较明显的增大.

Surface roughening and deformation of grains in uniaxial tension of polycrystalline titanium

Change in the surface morphology during tensile plastic deformation of polycrystalline titanium was consecutively observed and measured by the scanning probe microscope. The results show that the surface deformation is mainly due to slip for the plastic strain less than 0.1. Because a large amount of twins are formed and the second slip system becomes active, the surface roughness increases at the strain being 0.1 of the surface roughness-strain curve. The roughness, the maximum height difference, and the averaged slope angle of the microscope surface profile increase with the applied tensile strain.