Laser burnishing method for surface layer modification

The results of experiments on the application of a new hybrid method that combines laser melting treatment with burnishing in hot conditions are presented. Both treatments were performed on the laser station in one operation. The experiments were done on carbon steel C45. The process was performed with a CO2 laser of 2.5 kW maximum power at different parameters. Experiments on the influence of burnishing process parameters on surface layer properties were conducted. The results of measuring the roughness, microstructure, and micro-hardness of the surface layer after laser hardening and after laser hardening combined with microhammering are presented. The microhammering treatment leads to a decrease in surface roughness of about 40 per cent, compared with laser hardening alone. Neither cracks nor spallings were observed. Microstructural analysis has shown that the burnishing process causes deformation of grains and increased microhardness of the material of the surface zone.