Laser Alloying of Molybdenum on Steel Surfaces to Increase Wear Resistance

摘要

At the Institute of Material Science at the University of Hannover, investigations were carried out in close contact with the Laser Zentrum Hannover (LZH) concerning laser alloying of molybdenum on steel surfaces for increased wear. During the investigations, molybdenum was pre-deposited on the steel surfaces by plasma spraying and subsequently fused by means of Nd:YAG laser radiation (cw). To gain an extended process understanding, a video camera, sound emission analysis and a band pyrometer were used for process monitoring. The alloyed zones produced were examined using different test methods, such as electron disperse X-ray analysis (EDX). Adhesive wear tests were carried out with a pin-on-disc apparatus.In this paper, the employed process equipment and results concerning laser alloying of different pre-deposited molybdenum coatings will be presented. The process monitoring system used is a suitable medium for defining the beam/ material interaction. Using the sound emission analysis, for example, it was possible to qualitatively evaluate the crack intensity during alloying.