Research and Optimization of the Influence of Process Parameters on Ti Alloys Surface Roughness Using Femtosecond Laser Texturing Technology

Abstract

One of the major disadvantages of Ti alloys is their poor wear resistance. To increase their wear resistance, before applying a wear-resistant layer, the surface of the substrate should be carefully prepared to ensure the required coating adhesion. Femtosecond laser (fs) texturing is a technology that can be used for surface texturing of Ti alloys because it enables a controlled heat input on a small surface area. The process of laser texturing is very sensitive to the choice of input parameters, such as the number of passes (P) and laser power (W), the choice of which may significantly influence the ultimate surface roughness values (Ra). It cannot be expected that by using the fs process a given default Ra value will be achieved, but it is assumed that the obtained roughness values will be within the given interval. As a result of this research with a significance level of 95% using a design of experiments (DOE) and Monte Carlo simulations, a general linear model of Ra = f (P, W) and optimal input parameter intervals (P and W) of laser texturing were obtained both for the given interval as well as for the default surface roughness value (Ra). Considering that an industrial process is involved here, a process performance capability index (Cpk) has been also defined, which shows that optimal process parameter intervals give roughness values for the given interval or given default roughness value.