Effect of minimum quantity solid lubrication (MQSL) parameters on cutting force and temperature during turning of EN31 steel

Abstract

Considering the trends in the contemporary manufacturing and machining industry, dimensional accuracy, tool wear and quality of surface finish is becoming increasingly important. Hard-to-cut materials imposes two major difficulties, generation of high cutting temperature at tool and workpiece interface which subsequently leads to the increase in cutting force of the tool which ultimately increases the tool wear. The implementation of a proper lubrication system critically improves the surroundings of contact area by controlling the frictional relation which would ensure change in the machining mechanics. Minimum quantity solid lubrication (MQSL) is the process of supplying solid lubricant (molybdenum disulfide and graphite) along with oil at minimum quantities. In the present study turning experiments were performed by varying MQSL parameters (nozzle distance, compressed air pressure, lubricant flow rate and concentration of solid in lubricant) to comprehend the MQSL performance on cutting force and cutting temperature in turning EN31 steel. For this, a portable and cost-effective high velocity MQSL set-up was developed. MQSL performance was compared with wet and dry turning results. The present work offers a comprehensive picture which helps in ultimate the effect of lubricant parameters of MQSL in turning of EN31 steel.