Modelling of specific energy requirement during high-efficiency deep grinding

Grinding is a multi-point cutting operation. The specific energy or the energy expended for unit material removal in grinding is very high, typically one or two orders higher than the machining specific energy. Such high specific energy required in grinding can be attributed to the irregular and random geometry of the abrasive grits, which induce a lot of rubbing and ploughing actions along with the chip formation by shearing process. Also the effective angle in grinding is highly negative which is again responsible for such high-specific energy requirement in grinding. In grinding, a number of notable phenomena occur during the chip formation process, which actually consumes a significant percentage of energy. Such main energy consumers in grinding are: Chip formation due to shearing Primary rubbing Secondary rubbing Ploughing Wear flat rubbing Friction between the loaded chip and workpiece Friction between bond and workpiece, etc. The present paper tries to analytically predict the specific energy consumed during high-efficiency deep grinding (HEDG) of bearing steel by monolayer cBN wheel. During the HEDG process, energy is spent mostly for shearing, rubbing and ploughing processes. The other energy consumers have insignificant role in such high-speed grinding process. So, models which take into account the processes of shearing, primary rubbing, secondary rubbing and ploughing process can reasonably be used to predict the energy requirement in such HEDG process. The total specific energy value obtained from the model has been validated with those experimentally observed values. A good trend matching of the modelled and experimental values have been observed and the root mean square error values have been found to vary between 7% and 11%. (C) 2008 Elsevier Ltd. All rights reserved.