Grinding temperature modeling based on a time dependent heat source

Abstract

Grinding is widely used as a finishing operation for improvement of surface quality. However, because of extreme ploughing and rubbing and high specific energy of the process the heat generation is very considerable. Some portion of the generated heat is transferred to the workpiece increasing its surface temperature. High surface temperatures may cause problems such as surface burn, microstructural changes and phase transformations, reduced micro hardness, high residual stresses, white layer formation and decreased fatigue strength of the workpiece. Predicting of the grinding temperature is the first step for analysis and prevention of these problems. Because of the height differences of girts randomly distributed on the wheel, the grinding force is periodic. The fluctuation is more pronounced when the grinding is accompanied by the wheel run out. Accordingly, heat flux into the workpiece is not continuous and is a function of both location and time. In this paper, a grinding temperature model is developed based on a time dependent heat source to predict temperature of the workpiece. The proposed model is validated by measuring workpiece temperature. The results showed that the new model predict the maximum temperature of the workpiece 10-15 percent higher. A good agreement is observed between the model results and experimental data.