Energy Partition and Cooling During Grinding

High temperatures in grinding can cause thermal damage to the workpiece. This paper presents an overview of quantitative methods to calculate grinding temperatures and the energy partition to the workpiece. It is shown that the energy partition, and consequently the grinding zone temperature, depends on the type of abrasives, fluid application conditions, and grinding process parameters. For regular grinding with conventional aluminum-oxide abrasive wheels, the energy partition typically ranges from 60% to 85%. However, for creep-feed grinding with slow work speeds and large depths of cut, cooling by the fluid at the grinding zone reduces the energy partition to less than 5%. For grinding with cubic boron nitride (CBN) superabrasive wheels, the energy partition is about 20% due to the high thermal conductivity of the CBN abrasive. However, this may be reduced from 8% to 5% for grinding with porous vitrified CBN wheels at high removal rates due to the combined effect of the high thermal conductivity of CBN abrasive and cooling by the fluid at the grinding zone.