Phase Transformation and Stress Distribution in Polished PCD Composites

With the aid of the Raman spectroscopy, this paper investigates the phase transformation and residual stress distribution in surfaces of polycrystalline diamond composites polished by dynamic friction technique. To clarify the contribution of phase transformations to residual stresses, the study focused on the surface which was incompletely polished such that the transformed phases remained. It was found that amorphous non-diamond carbon and amorphous graphite phase appeared in grain boundaries, but pristine diamond phase was predominant within gain areas. The residual stresses vary across the polished surfaces and the maximum stress locates at the grain boundaries.