聚晶金刚石复合片(PDC)残余应力的检测方法

Methods for measuring residual stress in polycrystalline diamond compact

本文介绍了三种近期国外检测PDC残余应力的方法:应变片测试法、中子衍射法和带高能同步加速器X射线衍射法。三种方法均能有效检测出PDC的残余应力且各有其特点。应变片测试法比较直观、简单,不过这种方法是破坏性的,而且在材料去除过程中容易引入误差;中子衍射具有较深穿透力,然而较弱的散射使其取样体积不能小于1 mm3;高能同步加速器产生的散射X射线能穿透直径19 mm的PDC样品,空间分辨率高,测量体积可精确至0.014 mm3,能详细地呈现出金刚石层、D/WC界面以及WC基体外径部分的二维应变分布情况,但测试易受Co峰的干扰。

The authors introduced three methods for measuring the residual stresses in polycrystalline diamond compacts which are, rosette strain gauge, neutron diffraction stress measurement and energy dispersive X- ray diffraction（EDXRD）. Each method can be used to measure the residual stresses in PDC effectively and has its own characteristics. The first method is simple and easy to understand, but it is destructive and can easily result in inaccuracies during material removal. Neutron diffraction allows deep penetration into specimens due to the weak scattering of the neutrons. However, the weak scattering precludes sampling volumes of less than about 1mm^3. The high penetration capability and spatial resolution of energy dispersive X - ray scattering of the synchrotron radiation enabled detailed two dimensional mapping of strain in the entire diamond table, at the diamond/WC interface, and around the outside diameter of the WC substrate. The gauged votume is calculated to be 0. 014 mm^3 , however,the measurement may be interfered by Co peaks.