Abstract:
Machining is a widely used manufacturing process. This work explores the simultaneous machining by two single point cutting tools to enhance the productivity of the turning process. In order to perform a double tool turning process a conventional lathe was modified. A tool holding fixture was developed and mounted at the rear side of the lathe carriage. In double tool turning process the various process parameters are cutting speed, feed, depth of cut and distance between the two cutting tools. Experimental investigation was carried out to determine the influence of cutting parameters on cutting forces, cutting temperature, cutting tool vibration, diametral error, tool wear and surface roughness. The chip morphology was also studied.In the present work, it was observed experimentally that the rear cutting tool experienced lesser cutting force than front cutting tool at certain cutting condition, while turning grey cast iron. This is attributed to the reduction in coefficient of friction of the rear cutting tool, caused by the cleansing effect of the front cutting tool. At other cutting conditions, there is no significant difference in cutting forces between the front and rear cutting tool. It was found that the temperature rise in the workpiece caused due to the front and rear cutting tool remained uninfluenced by the distances between the cutting tools. An analytical model was developed for single tool turning process based on ductile fracture mechanics approach and experiments were also performed on mild steel work material. The analytically predicted cutting force and cutting temperature was correlated with the experimental results. For the selected cutting conditions it was observed that with the increase in cutting speed the cutting tool vibration of both the tools reduced. The rear cutting tool vibration was lesser than the front cutting tool. One obvious reason is that the rear cutting tool is mounted over the fixture made of cast iron while the front cutting tool fixture is made of steel.
