纳米级超显微硬度法对镉变形行为的研究

Deformation Behaviour of Cadmium As Determined Using A Nano Indentation System

利用纳米级超显微硬度压痕法研究了具有六方密排结构纯Ｃｄ（９９９９％）的应力应变及加工硬化行为·根据载荷压痕贯穿深度的测量，证明了在Ｃｄ的压痕变形中存在弹性、弹塑性和完全塑性三个阶段，与每个阶段相对应在其载荷压痕深度曲线上都出现一个斜率的改变，从而可以近似确定金属开始塑性变形的应力范围·其加工硬化指数是随着施加的最大载荷由５ｍＮ时的０１增加到４０ｍＮ时的０３，这主要是和加载的速度有关并满足线性方程·

The room temperature deformation behavior of high purity(99 99%) cadmium was studied using a nano indentation system. The measurement of load penetration shows that three deformation stages of elastic flow,elasticlpastic flow and full plastic flow exist in the deformation of Cd. The slope of load penetration depth curves changes corresponding to each stage. The material constant i.e.yield strength can be approximately determained from this slope change. When the maximum exerted force increases from 5mN to 40mN,strain hardening index increases from 0 1 to 0 3 and are linearly related to loading rate.