Comparative evaluation of machining performance of inconel 625 under dry and cryogenic cutting conditions

Hast alloys, wasp alloys and tool steels are the most commonly used materials in nuclear engineering and aerospace industries. However, these materials are considered to be “Difficult to machine” which attracted several researchers to work in this domain with a view to obtain optimum machining performance. The present work explored the comparative evaluation of machining performance of Inconel 625 under dry and cryogenic cutting conditions from an industrial perspective with emphasis on cutting forces, tool-chip interface temperature, surface finish and tool life. Turning experiments which were planned using the orthogonal array of L27were carried out using Tungsten carbide Al2O3 coated inserts varying the cutting speed, feed and depth of cut. Cutting forces generated during turning at varying cutting conditions were measured using three axis lathe tool dynamometer. It was found the combination of speed of 200 m/min, feed value of 0.04 mm/rev and depth of cut value of 0.2 mm gives the optimum cutting forces with superior surface finish and low tool chip interface temperature in dry cutting condition. Again for same combination of cutting parameters were tested with cryogenic coolant Liquid Nitrogen ( LN2) and it was observed that cutting forces reduced up to 30%, surface roughness improved by 31.37% and temperature reduced by 71.67%.