Preliminary Study of Ultrasound-Assisted Laser Hardening of AISI H13 Tool Steel

Abstract

This paper presents the viability of ultrasound in assisting the performance of laser hardening process. A nanosecond pulse laser was employed as a heat source in this study to heat and introduce hardened phase in AISI H13 tool steel. The influences of laser power and traverse speed on surface roughness and case depth of laser-irradiated region were experimentally investigated. The laser processing with the assist of ultrasound can improve the surface roughness of laser-hardened area by 7.5% and also increase the case depth by 7.65% compared to the non-ultrasound condition. Under a suitable processing condition, the laser can harden and polish the metal surface at the same when the ultrasound was incorporated in the process. The implication of this study will broaden the viability of ultrasound in the laser surface hardening/polishing of metals.