Selective Surface Modification of Complexly Shaped Steel Parts by Robot-Assisted 3D Scanning Laser Hardening System

Laser surface hardening is one of the most advanced surface modification techniques to increase the wear resistance of large-sized and complexly shaped metal products. In this study, the laser transformation hardening process for the high-quality surface treatment of the steel products is applied using a high-power disc laser with extremely good beam quality and three-dimensional (3D) scanning optics. The shaft AISI 1066 steel part was selectively processed by the robot-based laser hardening system to increase the surface hardness. At the same time, such a computer numerical control (CNC) laser system is ideal for remote surface treatment of complexly shaped metal products. The experimental tests with a solid-state disc laser of a maximum power of 5.3 kW were performed with a constant power strategy. Both plane and cylindrical areas on the shaft were hardened and compared. The results showed that the hardness values on the plane surfaces correlate well with the hardness values on the cylindrical surfaces. The hardening intensity was about 2.5 times higher than that of the unhardened carbon steel shaft.