The polishing of diamond

Experiments on the analysis of the wear debris produced during the polishing of diamond and the rapid sliding of diamond upon diamond using a high-speed sliding machine are presented. The debris was studied by electron energy loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) and by transmission electron microscopy (TEM). The aim of the work was to improve understanding of the polishing process. It was found that the debris produced when polishing diamond in a direction on a plane consisted of less dense forms of carbon. Diamond debris was instead found in the experiment with the high-speed sliding machine, but the wear track showed markedly different features from those observed on a surface after conventional polishing. The results suggest that the polishing of diamond in the soft directions occurs by a process in which diamond transforms to less dense forms of carbon, after which the transformed material detaches.