Femtosecond laser processing of advanced technical materials

Abstract

Ultra-short pulsed laser ablation may be used for high-precision machining with very low thermal influence on the processed materials. Due to this reason, lasers are increasingly used for processing of advanced materials, such as titanium alloys, nickel-based alloys or steel, every year. In this study, four advanced technical materials were analysed and compared under femtosecond laser irradiation with three different wavelengths. The main laser-material interaction parameters were identified, namely the ablation threshold and removal efficiency parameters. Higher removal rates were found for Ti6Al4V alloy with all three harmonic wavelengths. To increase process productivity, a method of increasing the repetition rate and scanning speed was presented. With the maximum repetition rate, the productivity increased five-fold with a similar removed depth and surface quality. Finally, the suitability of the identified parameters with regard to quality and productivity was demonstrated for fabrication of two complex structures – honeycomb and dot – which has the potential to improve friction properties of advanced materials.