Xu Guoping1,2, Yin Zhimin1, Chen Qiwu2, Xu Gen1
(1.School of Materials Science & Engineering, Central South University, Changsha 410083,Hunan,China)
(2.Changsha research institute of mining and metallurgy,Changsha 410012,Hunan,China)
Abstract The differential thermal expansion of the polycrystalline diamond layer and the tungsten carbide substrate results in large residual stresses as PDC cutters cooling after sintering. The residual stresses on the top surface of the diamond layer of PDC were measured at five points along the radial direction of PDC using X-ray Diffraction Residual Stress Instrument, thus the stresses and their radial distribution were obtained. The results show that the stresses on the diamond surface are compressive, the biggest stress appears at the central point (about 1200 MPa), and that from the center to the edge of PDC, the magnitude of the stress decreases. A finite element analysis (FEA) was made to check the validity of the testing results. The FEA modeling results were found to correlate well with the measured values. Factors leading to the deviation between XRD experimental measurements and the calculations of residual stress by FEA were also analyzed .