Pulsed Laser Micro Polishing of Metals Using Dual-Beam Technology

In this paper laser micro polishing with an additional laser beam for pre-heating of the surface is examined. Under the influence of the following process parameters on the surface roughness, the present work has been examined Pre-heating laser power, scanning velocity, beam offset of the two laser beams, and intensity distribution of the pre-heating laser beam. Two materials behavior have been used for investigation (martensitic tool steel and TiAl6V4), usually performed by different researchers in last two decades, for martensitic tool steel the micro roughness was increased in comparison to conventional laser polishing with only one laser beam (single-beam technology) due to increasing formation of martensite. For TiAl6V4 the meso roughness of the surfaces was decreased in comparison to conventional laser micro polishing due to longer melt duration, so smoother surfaces were obtained (up to 36 % lower surface roughness for one spatial wavelength regime).