Features of Using Metal Coatings on Diamond Grains in Electrically Conductive Grinding Wheels When Machining Polycrystalline Superhard Materials

Abstract

The paper focuses on the theoretical and experimental studies of metal bonded diamond grinding wheels, which are used for the single-point cutting tools finishing. Grinding wheels with coated diamond grains were analyzed. The effect of coatings on the stress-strain state of the system “bond – diamond grain – metal phase – coating – workpiece” was studied. A significant decrease of the stresses in the system compared to the wheels with uncoated diamond grains was found. The presence of coatings significantly improves the retention of the wheels grains and opens up the new possibilities for the control of the wheels cutting relief in a grinding process. Metal coatings on abrasive grains also play a positive role in the combined grinding process with the electrochemical effect due to an increase the electrical conductivity of a wheel and stabilizing its cutting relief. The issues of directional shaping of the cross profile of the wheels working relief in a grinding process were considered. A mathematical model of the electrochemical effects on the wheels working surface has been developed to provide the integrated relief control.