High-speed laser micro polishing of TiAl6V4

Abstract

In the present paper, laser micro polishing of TiAl6V4 is investigated with main focus on increasing the area rate by using high pulse energy. First, the influence of the laser beam size, the scanning velocity, and the track distance on the final roughness is examined since these parameters determine the area rate. The results of these investigations are used to identify a set of process parameters that allow increasing the area rate and achieving a surface roughness comparable to state-of-the-art laser micro polishing. The results show that the laser beam size must exceed a critical size; otherwise, smoothing of the surface is limited, which leads to higher final roughness. The scanning velocity and the track distance do not have a great effect on the final roughness for the investigated regimes. However, with decreasing track distance, the number of undesirable surface structures, presumably resulting from evaporating vanadium compounds, is reduced. Additionally, the heat input into the surface decreases with increasing laser beam size, scanning velocity, and track distance. The results of these investigations are used to significantly increase the area rate to 19.1 cm2/s, which is a factor of 64 times faster than the state of the art. The final surface roughness is comparable to state-of-the-art laser micro polishing in this case.