Performance of TiAlN PVD Coated Carbide Drill when Drilling Titanium 6246 Alloy

Abstract

This article describes the TiAlN PVD coated carbide drill tool performance after being used for drilling of Ti-6246 Titanium alloy. Every drill bit was used for single drilling and then being observed with SEM from flank and rake view. Taguchi method L18 design of experiment was used to find the optimum parameters. Wear was not found in this research, however, the tool delamination and tool chipping was evidenced, even if drilling only 10 mm depth. Tool experienced built-up edge in the outer blade, inner blade and at the chisel. This BUE can be seen at both view, i.e. rake and flank sides. BUE is the most dominant deterioration and inevitably in drilling this alloy, regardless the parameters applied. Tool delamination may occur during mechanism of peeling off the BUE. While chipping was related to higher feed rate, that may relate to high MRR. Analysing data using Minitab 17 shows that combination of drilling without cooling, 30 mm deep, cutting speed of 50 m/min and feed rate of 0.15 mm/min would result in the best performance of TiAlN tool for drilling Ti6246 as received.