Analysis of Grinding Temperatures by Energy Partitioning

Abstract

The partitioning of heat between two sliding bodies depends strongly on the relative magnitude of the thermal characteristics of each body. Grinding with the superabrasive CBN (cubic boron nitride) gives the favourable condition of a high thermal conductivity wheel, allowing increased heat to be carried away by the grinding wheel. This reduces the temperatures experienced by the workpiece. In this paper different methods of theoretical partitioning in grinding are reviewed. The partition ratio is the proportion of the total grinding energy that enters the workpiece. The partition ratio in surface grinding was measured using a thermocouple technique. Theoretical models for predicting the partition ratio were correlated with measured results to establish the effective thermal properties of CBN and aluminium oxide abrasives. The effective thermal conductivity of CBN was found to be considerably lower than the reported theoretical value. The findings provide the basis for improved prediction of workpiece temperatures in grinding.