聚晶金刚石复合片热残余应力分布规律实验研究

利用改进的应力释放法、X射线衍射法以及Raman光谱,对平面界面结构金刚石复合片表面热残余应力分别进行了实验研究,得到了金刚石层表面热残余应力值及其分布规律,同时得到了基体厚度与热残余应力的相关关系.研究结果表明,采用应力释放法、X射线衍射法及Raman光谱法测试PDC表面热残余应力,其测试结果均与有限元分析结果相吻合,证明了这三种方法的有效性.其中,X射线衍射法测试结果的误差最大,应力释放法其次,Raman光谱法最为精确.由于应力释放法应变片尺寸及X射线衍射法光斑照射范围的限制,无法在试样表面上取较多的测试点,因此难以得到理想的热残余应力分布曲线.而Raman光谱法中所采用的激光光斑仅5μm,可以取更多的测试点,因此其结果更能真实的反映金刚石层表面热残余应力的分布规律.本文的研究结果为精确测试PDC热残余应力,从而为优化PDC界面结构、提高PDC使用性能提供了理论和实验依据.

EXPERIMENTAL RESEARCH ON THE THERMAL RESIDUAL STRESS DISTRIBUTION OF POLYCRYSTALLINE DIAMOND COMPACTS

Thermal residual stresses of Polycrystalline diamond compacts (PDC)were tested using the stress release method, X-Ray diffraction and Raman spectroscopy. The distribution of thermal residual stresses and the relationship between residual stress and substrate thickness were presented.The obtained results show that the test results obtained by the stress release method,X-Ray diffraction,and Raman spectroscopy were highly closed with that obtained by finite element analysis. It's impossible to set much more test points on the surface of diamond table due to the dimension restriction of strain gauge and diffraction when using the stress release method and X-Ray diffraction. Therefore, the residual stress distribution curves obtained by these two methods both are not ideal. While the dimension of laser facula in Raman spectroscopy test takes only 5 μm, five or more test points can be set, which overcome the defects mentioned above.