Development and analysis of scalable laser machined surface utilizing low power nanosecond laser on Ti-6Al-4V alloy

Abstract

ABSTRACT A low-power fiber laser system was utilized for machining a scalable surface area on the Ti-6Al-4V alloy surface through the track overlapping process. The effect of laser power and track overlapping on laser machined surfaces was investigated. The experimental results revealed that the laser machined surface characteristics, i.e. machining depth, resolidified layer thickness, heat affected zone (HAZ) size, and surface roughness, depend on the average laser power and track overlapping. The increased laser power from 30 W to 50 W at 50% track overlapping increases the machining depth from 88 µm to 981 µm due to a higher energy supply. Further, laser processing at higher power, i.e. 50 W, shows a significant increase in resolidified layer (up to 727 µm). The laser machined surface generated at higher power and track overlapping increases the surface roughness. The laser machined surface developed at 30 W and 50% track overlapping indicates surface roughness (Ra) of 2.9 µm and increases to 6.5 µm for surface processing at 80% track overlapping. Further, the surface roughness of the laser machined increases up to 14 µm for laser processing at higher power (50 W) and high track overlapping (80%).