INVESTIGATION OF LASER PARAMETERS ON Ti-6AL-4V TITANIUM ALLOY FOR DIMPLE GENERATION USING HYBRID OPTIMIZATION TECHNIQUE

Surface-modified Ti-6AL-4V titanium alloy finds application as a biomedical implant. There are varieties of processes existing for surface modification, and laser surface texturing is one among them. In this research micro dimples are generated on the titanium alloy using a laser, and the effect of laser parameters on the contact angle (A) and dimple diameter (D) is studied. The variables, such as dimple distance (DD)in µm, laser power (E) in watts, laser frequency (F) in kHz, and standoff distance (SOD) in mm, were considered as input factors. L18 Orthogonal array was considered as an experimental plan, and Criteria Importance through Intercriteria Correlation (CRITIC) - Grey Relational Analysis (GRA) was used to analyse the result. Using the CRITIC method, the weights for the contact angle and dimple diameter were evaluated as 0.48 and 0.52, respectively. Based on GRA, the optimal combination is 100µm, 30 W, 60 kHz, and 227mm for better output performance, and as per Analysis of Variance (ANOVA), dimple distance and laser power are the primary parameters that determine the contact angle and dimple diameter; they contribute a higher proportion of 31.85% and 38.48%, respectively.