LASER SURFACE POLISHING OF TITANIUM ALLOYS

Abstract

This thesis explores and investigates the optimization of laser parameters for the enhancement of Surface and Mechanical properties of Ti-6Al-4V titanium alloy components through laser surface polishing. The study employs Laser Polishing conducted in two distinct environments: argon and nitrogen, utilizing an nanosecond pulse laser. Various combinations of remelting parameters were systematically tested, and each processed sample was meticulously analyzed for surface morphology, microstructure, surface roughness, and mechanical properties, including microhardness. The experimental results demonstrate that laser remelting in an argon environment yields significantly improved surface roughness compared to remelting in a nitrogen environment. Furthermore, the tribological properties of the titanium substrate were notably enhanced when processed in argon. The high heating and cooling rates inherent to the laser irradiation process facilitated the formation of refined microstructures in both argon and nitrogen environments. Remarkably, the hardness of Ti-6Al-4V remelted in argon exhibited an increase of up to 100% compared to the untreated substrate. These findings underscore the efficacy of argon-assisted laser remelting in significantly enhancing the surface and mechanical properties of titanium alloys, highlighting its potential application in advanced manufacturing processes.