Study on the coolant supply method in grind-hardening

The grind-hardening is a type of surface modification technology, which utilizes the dissipated grinding heat for hardening the workpiece surface. This technology integrates the surface hardening with surface finishing. Grind-hardening was usually performed dry to maximize heat generation or performed with the conventional coolant supply method. However, the workpiece often was unable to be hardened due to lower cooling rate in dry grind-hardening or insufficient temperature rise in the conventional wet grind-hardening. A new coolant supply method was introduced in this study. Using this new method, it was found that the grinding heat can be utilized efficiently while keeping the surface layer of the workpiece at high cooling rate. Comparing with other coolant methods, the new coolant supply method has many advantages, such as higher hardness, higher hardness penetration depth, and finer martensitic structure.