聚晶金刚石复合片的残余应力测试与研究

Residual stress of polycrystalline diamond compact

聚晶金刚石复合片产品内部普遍存在残余应力,这是造成其非正常失效的主要因素。我们详细研究了金刚石复合片内部残余应力的组成,并采用X射线衍射仪建立了聚晶金刚石复合片残余应力的检测方法,研究了聚晶金刚石复合片的残余应力分布规律。利用XRD检测残余应力的方法,分别研究了聚晶金刚石层厚度、金刚石粒度尺寸、两相界面结合形状以及金属Co对复合片的残余应力的影响规律,为控制PDC内部应力提供参考。结果显示:金刚石层表面残余应力最大的压应力在中心位置,从中心到边缘,应力的大小逐渐降低;PCD层与硬质合金基体界面附近的应力值对PDC使用性能的影响最大。

Residual stress is widely spread in polycrystalline diamond compact（ PDC） products,which leads to failure PDC. In this research,we studied the composition of residual stress and established an inspection method to analyze residual stress by using XRD. The distribution rule of the stress is also discussed. The influence of thickness of PCD layer,size of diamond particle,shape of interface and content of Co on PDC residual stress is studied to provide a reference for residual stress control. In conclusion,it is showed that： 1） on the surface of diamond layer,the maximum appears in the centre and decreases along radial direction; 2） the stress near the interface between PCD layer and carbide matrix has significant influence on service character of PDC product.