Adaptive laser-based local transformations of the magnetic properties in austenitic stainless steel using optical feedback

Abstract

This paper presents a laser-based system for a local transformation of the magnetic properties in austenitic stainless steel. The process is applied to linear actuators with an integrated, in-axis position measurement where durability and high precision are needed. The developed system consists of a 400-W, single-mode fiber laser, the focusing optics, and a three-axis actuation system. An important feature is the optical feedback for the adaptive, high-speed (40 kHz) laser power regulation. The experimental results show that the optical feedback effectively compensates for the external disturbances, like an increased roughness and a gradual heat accumulation. The regulation decreases the dispersion of the magnetic signal’s response by more than 100% and shortens the transient time at the beginning of the inscription process from 100 to 15 ms.