Laser surface texturing of β-Ti alloy for orthopaedics: Effect of different wavelengths and pulse durations

In this work laser surface texturing of Ti-11.5Mo-6Zr-4.5Sn β-Ti alloy is investigated with different laser wavelengths and pulse durations. For benchmark purposes, three different industrial solid-state laser sources providing four different wavelength/pulse duration combinations were used. Within the experimented range pulse duration could be varied at 2.5 ps, 6 ns and 250 ns at 1064 nm, while 5 ns pulse duration was tested at 355 nm. The comparative analyses were carried within the process parameter ranges available to the laser sources in order to assess the quality and productivity aspects. In particular, surface roughness, wettability, and chemical composition were quantified as well as assessing the distinct surface morphologies obtained with different configurations. Process productivity was analysed for each configuration in terms of machining rate. The results exhibit a large variety of possible surface textures available to biomedical implant designers with nanometric to micrometric features and tailorable chemical and wetting properties. Moreover, the results help in understanding how the light/matter interaction changes between different pulse durations and wavelengths.