Single crystal diamond grits with a 600 Am mesh size were used as grinding grits capturing the interaction between grinding wheel and workpiece under low to high grinding speeds. The analysis considered the critical depth of cut corresponding to the brittle/ductile material removal transition, machined groove morphology carried out with AFM (Atomic Force Microscope) and SEM respectively. Subsurface integrity of the machined groves and wear mechanisms of the diamond grit after single grit grinding were also considered. The results showed that the single grit grinding method integrated with the advanced on-position monitoring methods and imaging techniques is capable of providing accurate fundamental data and defines guidelines for realizing ductile machining of brittle materials with high surface quality.

A Ni–Cr–B–Si/10vol%WC coating material has been precision ground to an optical quality surface finish (<10 nm Ra) using a combination of a very stiff precision machine tool, Tetraform “C”, 76 μm CBN grinding wheels and electrolytic in-process dressing (ELID) assisted grinding. When grinding without ELID, surface finish has been shown to be limited by damage to primary and secondary carbides. This damage may be in the form of carbide pull-out or localised fracture and removal of the larger primary WC particulate. ELID assisted grinding helps maintain CBN grit protrusion and sharpness and thus promotes efficient cutting during grinding, minimising pull-out and localised damage to the harder phases within the coating microstructure. ELID therefore improves both the overall surface finish and surface integrity of the workpiece.