Evaluating the machinability of Ti-6Al-4V using coated carbide inserts

The objective of the work is to perform precision turning using a conventional lathe on Ti-6Al-4V under dry working conditions. Various parameters that affect the machining process were identified and a consensus was reached regarding its values. Precision turning is a type of machining where very low feed rate and depth of cut are being used to machine using a cutting insert with a lower nose radius. The cutting parameters considered for the experiments include the cutting speed, feed rate, depth of cut and nose radius. The machinability of Ti-6Al-4V was investigated by some researchers using coated carbide inserts, but its machinability using advanced cutting inserts was not explored adequately. PVD coated carbide cutting inserts with different nose radius and constant rake and clearance angle are being considered for experimentation. The experimentation was designed based on Taguchi's L 27 orthogonal array. Three different levels of cutting parameters were being considered for the experimentation. The turning experiments were carried out on a conventional variable speed motor lathe under dry working conditions. The machinability is evaluated in terms of surface finish achieved on the work piece, tool wear encountered and tool life achieved by the inserts for various precision machining time and the cutting zone temperature generated during the process.