Performance Evaluation of PVD and CVD Coated Inserts during End Milling with Dry and MQL Condition

Abstract

The aim of this study is to evaluate the performance of PVD (TiAlN+TiN), (TiCN+TiN), and CVD (TiCN+Al2O3+TiN. 0315), (TiCN+Al2O3+TiN) coated inserts in end milling of EN–31 hardened die steel of 43±1 HRC during dry and MQL machining. The experiments are carried out at two different stages. In first stage experiment is conducted at a fixed feed rate, depth of cut and varying cutting speed to measure the effect of cutting speed on cutting force, tool wear and surface roughness of different CVD and PVD coated inserts whereas in the second stage, the experiment is conducted under fixed cutting parameter i.e. (depth of cut, feed rate and cutting speed). The experiments are performed to compare the tool wear, cutting force and surface roughness of these coated inserts under dry and MQL condition. It is concluded that PVD inserts provide less cutting force, tool wear and surface roughness as compared to the CVD inserts because PVD inserts have a thin coating thickness as well as CVD inserts has a thick coating thickness, but PVD inserts experience catastrophic failure during cutting operation whereas CVD inserts have a capability for continuous machining under different machining. Tool wear also measure by SEM analysis. SEM (scanning electron microscope) analysis is used to analyze the adhesion and abrasion wear which occur during cutting operation of the cutting tool. MQL machining provides good result among all cutting conditions as compared to the dry condition. MQL machining has ability to work under high cutting speed as well as high depth of cut. It decreases the tool wear, cutting force and provide a good surface of the machined part.