Tool wear characteristics in turning of titanium alloy Ti-6246

Research work has been carried out to determine the behaviour of titanium a lloys during the processes of turning. Most of the information available is based on observations made during the commercial production of titanium co mponents in the aerospace industry. Titanium alloys have been classified as 'difficult-to-machine' materials. These alloys are used widely where the s trength-to-weight ratio and corrosion resistance are of the utmost importan ce. In the present work, uncoated cemented carbide tools were used in the t urning of Ti-6% Al-2% Sn-4% Zr-6% Mo. The experiments were carried out unde r dry cutting conditions. The cutting speeds selected in the experiment wer e 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. SE M analysis has been carried out on the worn tools to determine the tools we ar 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 fa ilure was due to maximum flank face wear and excessive chipping on the flan k edge. (C) 1999 Elsevier Science S.A. All rights reserved.