Hybrid processing of bearing steel by combining direct laser interference patterning and laser hardening for wear resistance applications

In this study, a hybrid process for increasing the hardness and thus resistance of laser-generated surface textures by a laser heat treatment for functional surfaces is proposed. The process chain involves the fabrication of well-defined periodic surface features on bearing steel using Direct Laser Interference Patterning in conjunction with a laser-hardening process. The fabricated laser hardened layer exhibits a laser feed rate dependent thickness between 500 and 800 µm which additionally enhances the hardness of the patterned surface from 210 to 827 HV 0.1. The increased surface hardness directly translates into a significantly improved wear-resistance of the surface patterns, which exhibit up to ∼ 200 % of that of non-hardened patterns. The proposed hybrid laser texturing-hardening approach allows the generation of wear-resistant and at the same time intact surface patterns for harsh environmentssuch in tribological applications.