Experimental study and optimization of turning Inconel 718 using coated and uncoated inserts

Abstract

Abstract This work focus about investigation of development of cutting force and roughness of the surface produced while Inconel 718 alloy dry turning with coated and uncoated tool inserts. Inconel 718 is a super alloy which consists higher amounts of nickel and chromium due to which it poses higher tensile and impact strength at elevated temperatures. In addition to that it also poses excellent corrosive resistance. So eventually it became a widely used material in jet engines and gas turbine operations. But the machining of Inconel 718 is very challenging to the users because of strain hardening tendency. Tool aspects like geometry of tool, tool material and conditions of machining are the principle factors which influence the nature of machining. Hence, in the present work, investigation of turning parameters with two different tool inserts (coated -TiN and uncoated) on Inconel 718 are used for machining are studied. The turning tasks were done to discover the best working conditions. A total of 9 Experiments were performed by a new cutting edge of each insert (coated and uncoated) based on Taguchi’s strategy of experimentations to find out the best operating condition. The machining considerations are speed of spindle, depth of cut, feed and the performance characteristics are cutting forces and roughness of the surface. By comparing the results, it was observed that the cutting forces and the surface roughness of uncoated inserts are found to be high when compare with the turning of Inconel 718 coated tool. The coated tool is efficient with the low speed and the maximum depth of cut with the moderate feed. On the other end uncoated tool is reliable with the moderate speed and low depth of cut. The temperature generation also high in uncoated tool insert when compare to coated tool due to increase in temperature blunt or breakage of the tool chances are high in dry turning of Inconel 718 while using uncoated tool. The cutting speed is recognized as the most critical parameter for the turning activity as indicated by the weighted total evaluation of the cutting force and surface roughness.