The influence of process variables on machinability of hardened tool steel during the hard turning under eco-friendly cooling environment

Recent developments in cutting tool technology and its environmental impact have made significant revolutions in hard turning process thereby increasing the productivity level and enhancing the surface integrity of machined components competitively. In this experimental work, the machinability aspects, surface finish and tool life were investigated during hard turning of hardened AISI D3 tool steel work materials with wiper geometry ceramic inserts under eco-friendly compressed air cooling environment. The process variables such as cutting speed, feed rate, tool nose radius, hardness levels of work materials and compressed air pressure were considered for this study. Since the tool nose design influences the machinability aspects, the cutting tool nose radius was considered as one of the vital process parameters. The design of experimental sequence and analysis of experiment data were carried with the help of Design Expert, DOE software. The combinations of Taguchi L16 orthogonal array and ANOVA technique have been applied for evaluating the process outcomes with reference to cutting variables. From the current experiment results, it is observed that combination of wiper ceramic insert with large nose radius and lower levels of compressed air pressure and work piece hardness were resulting in higher surface quality with prolonged cutting tool life.