EFFECT OF CUTTING PARAMETERS ON CUTTING ZONE IN CRYOGENIC HIGH SPEED MILLING OF INCONEL 718 ALLOY

Abstract

In tribology phenomenon, surface roughness has become one of the most important factors that contributed to the evaluation of part quality during machining operation. In order to understand the behavior of cryogenic cooling assistance in machining Inconel 718, this paper aims to provide better understanding of tribological characterization of liquid nitrogen near the cutting zone of this material in ball end milling process. Experiments were performed using a multi-layer TiAlN/AlCrN-coated carbide inserts under cryogenic and dry cutting condition. A transient milling simulation model using Third Wave Advantedge has been done in order to gain in-depth understanding of the thermomechanical aspects of machining and their influence on resulted part quality. The cryogenic results of the cutting temperature, cutting forces and surface roughness of the ball nose cutting tool have been compared with those of dry machining. Finally, experimental results proved that cryogenic implementation can decrease the amount of heat transferred to the tool up to almost 70% and improve the surface roughness to a maximum of 31% when compared with dry machining. Furthermore, the microstructure of machined workpiece revealed that cryogenic cooling also can reduce a plastic deformation at the cutting surface as compared with the dry machining.