Laser micro-nano texturing of a polycrystalline ultra-hard cutting tool to improve wear behaviour

Polycrystalline diamond cutting tools are widely used for drilling and turning applications due to their high wear resistance and long durability, however the issue of adhesion of workpiece to the cutting tool significantly affects the cutting tool lifetime. Using a nanosecond fibre laser surface texturing of polycrystalline diamond single point cutting tools is proposed to improve diamond wear and anti-adhesion properties in machining aluminium alloys. The textures, with topographical features’ depths and pitch ranging from tens of nanometers to tens of micrometers, were first milled using a fibre laser (1064-nm wavelength) at different fluences, feed speeds and pulse durations, and finally characterised using a combination of Scanning Electron Microscopy, White Light Interferometry and Energy Dispersive X-Ray (EDX). The effect of different textures on the wear properties was investigated in turning tests under dry conditions. The tests were stopped every 20 passes and the wear analysed through an Alicona optical 3D measurements. The online monitoring and post-processing of the cutting forces and the microscopical characterisation of the tested cutting tools allowed the evaluation of the effects of texture design and adhesive properties. For textures depths in the order of 260nm and post process roughness in the order of tens of nanometers, a reduction of cutting force and an improvement of antiadhesive effect were achieved in dry turning.