Investigating the influence of shielding gas stability of laser polished Ti-6Al-4V alloy using image processing

Abstract

The use of Additive Manufacturing methods in modern manufacturing is increasing rapidly. However, the high surface roughness of the manufactured parts is a major drawback for Additive manufacturing methods. Therefore, additively manufactured parts need subsequent surface treatment. Laser polishing (LP) is one of the nontraditional polishing techniques, where a shielding gas is also used during the process to eliminate the adverse effects of the atmosphere. In this study, additively manufactured Ti-6Al-4V samples were laser polished by using Argon as shielding gas. During the operation, the flow stability of shielding gas was changed to observe the consequences of gas flow instability during LP. This observation was carried out by using Image Processing techniques. Even though surface quality alteration is possible even with an unstable gas flow, the output of surface modification may differ along with the material, especially in terms of surface roughness. The surface quality of the sample which processed under a stable Argon flow gave homogenous results, while the sample which processed under an unstable Argon flow gave non-homogenous results on its surface.