Polishing of polycrystalline diamond by the technique of dynamic friction, part 3: Mechanism exploration through debris analysis

This paper investigates the mechanisms of material removal in dynamic friction polishing of polycrystalline diamond composites through the analysis of polishing-produced debris. The specimens used were PCD compacts composed of diamond and silicon carbide. In order to uncover the debris’ structure, high-resolution transmission electron microscopy (HRTEM), electron diffraction and electron energy loss spectroscopy (EELS) were used. Additionally, the density and the sp2 to sp3 ratio in the hybridized carbon materials of the debris were estimated from the EELS spectra. It was found that the debris were mainly of amorphous structure and consisted of different forms of carbon, silicon oxide/carbide, iron oxides, etc. The results show that during polishing, the diamond has transformed to non-diamond carbon, and silicon carbide to amorphous silicon carbide/oxide.