<title>Full-field IR measurement of subsurface grinding temperatures</title>

Abstract

A multiple-element, forward looking IR system is used to measure the subsurface temperature field produced by dry grinding of steel with both aluminum oxide and cubic boron nitride (CBN) grinding wheels. The technique is base don imaging the IR radiation obtained from the side of the specimen. A recent theoretical analysis of heat partition and surface temperatures in grinding is reviewed. The analysis partitions heat on the two length scales pertinent to grinding between the workpiece, wheel, coolant and chips. Spectral analysis is combined with FFT techniques to calculate subsurface temperature contours from the predicted heat partition. The numerical predictions of the model are shown to agree wit the experimental results taken for a range of grinding conditions. It is found that heat partition varies over a wide range depending on grinding conditions. Also, heat partition is a strong function of position inside the grinding zone. The presence of the fluid inside the grinding zone can reduce the heat flux into the workpiece and the workpiece temperature significantly. For typical grinding of steel with CBN, or creep feed grinding of steel with aluminum oxide or CBN, it is possible to keep the fluid active and therefore to reduce thermal damage. However, the analysis suggests that the fluid may not be effective inside the grinding zone, in the conventional grinding of steel with aluminum oxide, due to boiling. It is also found that a moderate ratio of the workpiece velocity to wheel velocity gives high temperatures and therefore should be avoided.