Residual stress analysis on electrical discharge lapping (EDL) of polycrystalline diamond

PCD is the combination of diamond particles that are sintered together under high temperature and high pressure conditions in the presence of catalytic metal. Due to its superior properties, this material has been widely used for cutting tool. However, magnitude and direction of residual stress obtained from the fabrication process believe to affect the tool performance during application. Furthermore, high temperature generated by the process might also contribute to the structure alteration that finally reduces the strength of PCD. This paper revealed that the residual stress due to EDL is more dominant in tensile direction which is vice versa to the conventional process. Analysis on the spectrum indicated that there is a relationship between the tensile stress value and the composition of graphite on the Raman laser spot location.