Xu Gen1 Xu Guoping2 Chen Feng3 Ma Chunde3
(1.School of Resources and Safety Engineering,Central South University,Changsha 410083, China)
(2.King-ray New Materials Science & Technology Co,Ltd,Changsha 410012,China)
(3.Testing Center,Central South University,Changsha 410083, China)
Abstract Practical experiences gained in the past several years show that the thermal residual stress (TRS) is a main cause leading polycrystalline diamond compacts (PDC) to premature failure. It is the very important to measure the TRS accurately for optimizing the interface and improving the service performance of PDC. In this paper, the TRS in 1913 flat-interface PDC was measured using improved stress-release method (ISRM). The TRS on the surface of polycrystalline diamond (PCD) table was obtained, which can be used to calculate the radial thermal residual stress (RTRS) at the interface of PCD table via a refutation process. The obtained results show that there are compressive residual stress at the PCD table interface and in the most region of PCD table surface. The exception occurs near the outer diameter of the PCD table, where the PDC begins to bend and put the PCD table surface into a tension state, an undesirable state for a brittle material. The ISRM has covered the shortage existing in traditional stress-release method, in which only finite points on the surface of PCD table can be tested for one specimen and one time. Simple as the experimental procedures are, the test results are also very accurate and reliable. This method provides the theoretical and experimental basis for testing TRS of PDC accurately.