Tool wear characteristics in turning of titanium alloy Ti-6246

Abstract

Research work has been carried out to determine the behaviour of titanium alloys during the processes of turning. Most of the information available is based on observations made during the commercial production of titanium components in the aerospace industry. Titanium alloys have been classified as `difficult-to-machine' materials. These alloys are used widely where the strength-to-weight ratio and corrosion resistance are of the utmost importance. In the present work, uncoated cemented carbide tools were used in the turning of Ti–6% Al–2% Sn–4% Zr–6% Mo. The experiments were carried out under dry cutting conditions. The cutting speeds selected in the experiment were 60, 75, and 100 m min −1. The depth of cut was kept constant at 2.0 mm. The feed rates used in the experiment were 0.25 and 0.35 mm per revolution. The effects of different types of chip-breaker geometry and grain size of the tool were observed. Tool wear was measured under an optical microscope and the tool life for machining titanium alloy, Ti-6246, was determined. SEM analysis has been carried out on the worn tools to determine the tools wear mechanisms. The results have shown that inserts with fine grain size and a honed edge have a longer tool life. At higher cutting speeds the tool failure was due to maximum flank face wear and excessive chipping on the flank edge.