Experimental investigation of ns pulse laser processing parameters for machining of Ti-6Al-4V alloy

Abstract

Traditional machining faces technical barriers in producing microfeatures when the workpiece poses high-strength and temperature-resistance characteristics. Laser is a possible machining approach that works effectively in the aforementioned conditions. The present study utilized a low-power fiber laser system machining of the Ti-6Al-4V alloy surface. The influence of laser processing parameters, for example average power, scanning speed, and pulse frequency, were analyzed on the laser-machined microgroove profiles using the full factorial design of the experiment. The results revealed that the fabricated microgroove profile characteristics, that is, depth, width, heat-affected zone (HAZ), surface roughness, etc. of laser-processed zone strongly depend on the laser processing parameters. Furthermore, the laser microgroove size, that is, depth and width, increases with the increment in laser power combined with low scan speed and low frequency. High laser power (50 W), low scan speed (0.1 mm/s), and low frequency (50 kHz) produce a microgroove with high depth (754.28 µm) and width (285.71 µm). It has been also observed that average power has the most significant impact on the machined surface profile, HAZ, and surface roughness. Moreover, it has also been observed that crack forms at the center of the machined surface is by decreasing scanning speed. Further, lower surface roughness is found at the highest pulse frequency. Hence, the present study recommends laser processing at lower power, high scanning speed, and high pulse frequency to generate a smooth and uniform machined surface.