Effects of fiber laser treatment on properties of Ti-64 alloy

Abstract

Titanium (Ti) is a metal used extensively in aerospace, automotive industry and medical implants due to its exceptional combination of strength, corrosion resistance, and biocompatibility. The researchers have shown a lot of interest in exploring the areas for further enhancement of properties of Titanium alloy and to widen the range of applications. In current years, laser treatment has gained attention as an attractive method to modify the surface properties of these alloys, aiming to enhance their mechanical, chemical, and biological attributes. This study systematically examines the impact of various laser parameters, such as scan speed, and laser power, on the microstructural changes, mechanical properties, corrosion resistance, and surface wettability of titanium alloys. In the present research, laser treatment was performed on Ti alloy to study its effect on surface properties by Fiber laser heat treatment (LHT). The Ti-64 alloy (Ti-6Al-4 V) was selected LHT carried out and the surface integrity of the Ti alloy was analyzed before and after the laser process. The fiber laser of power 1600 W with a scanning speed of 7 mm/s and frequency 5000 Hz was used and nitrogen was used as shielding gas with a pressure of 10 bar. Micro Vickers hardness test, Optical Microstructure and Immersive Corrosion test have been carried out to scrutinize the impact of the laser surface heat treatment process. In the microstructure, the coarsened alpha phase in the matrix of the beta phase was transformed into an elongated alpha phase after laser treatment, increasing the grain boundary and hence the hardness. It was noticed that there was a 9 % increase in the hardness of Ti alloy after LHT in comparison with before LHT. The corrosion resistance of Ti alloy was enhanced significantly after LHT.