Cutting force, chip formation, and tool wear during the laser-assisted machining a near-alpha titanium alloy BTi-6431S

Abstract

BTi-6431S is a promising material for aero-engine and supersonic speed aircraft parts application. However, the machinability of the alloy is relatively poor due to its high mechanical properties at high temperature. Laser-assisted machining (LAM) is a promising solution to reduce the cutting pressures when machining difficult-to-cut materials, such as Ti-6Al-4V alloy. In this paper, the machinability of this near-alpha alloy has been investigated in terms of cutting force, chip formation, and tool wear in different laser power conditions over a range of cutting parameters. This investigation shows that the BTi-6431S alloy is considerably less responsive to LAM compared to Ti-6Al-4V, and the tool life was not extended by using the LAM process for BTi-6431S. The main tool failure mode is flank wear and rake face chipping under conventional machining (CM) condition, while the diffusion wear is the main tool failure mode under LAM. The machinability of BTi-6431S near-alpha titanium alloy is significantly lower than that of Ti-6Al-4V alloy.