A VARIABLE HEAT-FLUX MODEL OF HEAT-TRANSFER IN GRINDING WITH BOILING

In grinding processes, the grinding fluid is used to suppress the temp erature rise in the grinding zone. Under some circumstances the grindi ng fluid may undergo film boiling in the grinding zone, causing the wo rkpiece temperature to rise significantly. The onsets of nucleate boil ing and film boiling in the grinding zone are investigated in the pres ent study. A model of heat transfer in grinding was previously develop ed (Jen and Lavine, 1995), which predicts the temperatures and heat fl uxes in the grinding zone. With some modification this model is used h ere to predict the occurrence of film boiling of the grinding fluid. T he dependence of the workpiece background temperature on the various g rinding parameters is explored. The workpiece background temperature d istribution along the grinding zone, and comparisons with experimental results, are presented.