Conventional and laser-assisted machining of laser-borided Monel 400 alloy

This study concentrates on comparing effects of conventional and laser-assisted machining (LAM) of laser-borided Monel 400 alloy. For this purpose, the shaft made from Monel 400 was covered with 200-µm thick boron layer and surface melted using diode laser. For determining the influence of laser beam scanning velocity on final microstructure, microhardness, and depth of melting, four laser beam scanning velocities were set: 5, 6, 8. and 10 m/min. Obtained microstructures are typical for laser-melted metal and are composed of fine crystals. Microhardness increased significantly due to enriching Monel 400 with boron and the level of this increase depends on the laser beam scanning velocity carried out for the process. During both conventional and laser-assisted turning, cutting forces were measured for comparison. Other compared parameters after carrying out these processes were obtained surface roughness and tool life. It was found that it is possible to form laser-borided surface of Monel 400 alloy by machining and using additional laser-assist has a positive impact on the efficiency of the process. Laser-assisted machining allows to lower cutting forces during machining and this leads to extended tool life. On the other hand, this method provides lower values of roughness parameters on the machined surface due to the effect of softening the surface during the process. The paper is the first description of effects obtained by laser-assisted machining of laser-borided surface.