Influence of minimum quantity lubrication parameters on grind-hardening process

ABSTRACTCurrently, dry grind-hardening has been studied to achieve a deep grinding harden layer. For dry grind-hardening process, the ground surface may have a poor surface quality. In our previous research, minimum quantity lubrication (MQL) has been proved as an effective way to improve the surface quality in grind-hardening process. Unfortunately, the relationship between the surface quality and parameters of MQL is still not clear. In this paper, different spraying parameters (fluid flow, air pressure, nozzle location, spraying distance) are investigated in surface grinding experiments of annealed steel AISI 5140. Grind-hardening performances are analyzed for grinding force and surface quality, such as surface roughness, micro-hardness, and grinding harden layer depth. Consequently, the results show that MQL can improve the grinding surface roughness and the micro-hardness of the grinding harden layer. The surface roughness can be improved with a better lubrication, which can be achieved with the appr...