Laser-Assisted Surface Treatment of Ti64 Alloy for Industrial Applications

Ti-6Al-4V is one of the most frequent titanium alloys used in biomedical engineering due to its outstanding properties that stem from its high strength-to-weight ratio, the unique combination of ease of machinability, good biocompatibility, and corrosion resistance. Such alloy is commonly used to manufacture biomedical implants, such as orthopedic, dental implants, and cardiovascular devices. This present study seeks to increase the corrosion resistance of Ti64 alloy using laser surface treatment. Laser surface treatment has been accomplished by melting the Ti64 surfaces using ultra-short pulses from a Q-switched Nd: YAG laser. Laser fluence (FL) with several values was utilized to accomplish the proper laser fluence which gives the optimal findings. After laser surface melting, the microstructure became more homogeneous with finer grain size, 2 µm for surfaces treated at 65 J.mm-2 vs. 145 µm for the untreated surfaces, this could be due to the quick self-quenching associated with the laser melting. The microhardness is improved to a maximum of 500 HV0.3 at 65 J.mm-2 due to the formation of needle-shaped martensite α` Ti phase after the rapid solidification. The results revealed a reduction in the corrosion rate from 0.75 µm/Y for untreated titanium alloy to 0.07 µm/Y for the laser-treated alloys consequently, it was confirmed that the laser fluence had a substantial impact on both surface hardness and corrosion resistance. In conclusion, the laser surface melting using nanoscale pulses from a Q-switched laser system could be applied to successfully enhance the corrosion resistance and the surface hardness of Ti64 titanium alloys.