油田钻探用金刚石复合片热残余应力分析

Residual Stress Analysis of Polycrystalline Diamond Compacts

目前国内外PDC钻头所使用的金刚石复合片有80%的非正常失效断裂是由其残余应力和界面结构问题引起的,热残余应力是造成金刚石复合片非正常失效的主要因素。根据金刚石复合片制造过程中的热力学工艺条件,对其平面界面热残余应力进行了详尽的数值计算和分析,对其热残余应力的分布规律和温度变化引起的变形规律进行了深入研究。研究结果表明,界面残余应力形态及其与金刚石复合片断裂失效存在内在关联,聚晶金刚石层厚度与残余应力及变形之间也密切相关。据此,提出了有效降低界面残余应力的措施。

Eighty percent of Polycrystalline diamond compacts （PDC） bits failure is caused by residual stresses and interface structure, and the thermal residual stresses is the main reason for PDC to failure. In this paper, thermal residual stresses in plane-interface PDC were studied using numerical methods. The thermal residual stresses distribution and deformation of PDC caused by temperature change was investigated. The results indicate that the brittle rupture mode of PDC is closely related to the distribution of thermal residual stresses, thickness of PCD layer is related to the residual stresses and deformation of PDC. The measures to effectively reduce the residual stresses were proposed in this paper.