Influence of pulse duration and pulse frequency on micro-roughness for laser micro polishing (LμP) of stainless steel AISI 410

Press plates for decorative laminates are often made from AISI410 and typically need a surface finish created by polishing. A new manufacturing process that can overcome disadvantages from conventional polishing processes is laser micro-polishing (L mu P). Therefore, this experimental investigation focuses on the effect of L mu P on the micro-roughness in the nanometer range for stainless steel AISI410. This study closes a gap regarding investigations for L mu P with pulse durations from 10 ns to 220 ns and pulse frequencies from 20 kHz to 240 kHz using a commercially available 35 W fiber laser. The feasibility for L mu P on AISI410 in terms of achieved microroughness and avoidance of surface defects was successfully demonstrated. A significant reduction of surface roughness was achieved using pulse durations as short as 10 ns and pulse frequencies as high as 240 kHz. In addition, indications for a fundamental change of the process from a discrete, pulsed process to a continuous remelting process were observed and an empirical estimation for the prediction of this change was derived. Furthermore, spatially resolved laser polishing was demonstrated on textured press plates. With area rates of up to several square meters per hour within reach, L mu P on AISI410 stands ready for industrial implementation.