Improving quality and performance properties of chemical coatings on steels and alloys by laser treatment

Abstract

The subject of this paper is the Ni-P chemical coatings on steels and alloys. The research goal is to determine the capabilities of improving the quality and performance properties of the coatings under the rapid laser processing. Metal physical research methods - optical and electron-probe microscopy, hardness measurement, X-ray and electron microprobe analysis - are used. Anti-friction properties of the irradiated coatings are determined under testing on the tribometer. The study results have shown that the laser irradiation of chemical coatings can increase the hardness of the steel surface layers, advance the adherence strength of the coating to the steel substrate, lower the friction factor, and enhance the wearability of the coated steels.The results obtained allow reasonably choose modes of laser processing for chemical coatings leading to the consolidation and degassing of the steel surface layers, the increase of the coating adhesion to the substrate, the improvement of the surface morphology, the formation of a relatively perfect texture in the steel surface layers, and to the reduction of the burnout of alloying elements from the surface layers of materials.The studies show that the laser treatment of chemical coatings improves the quality of the surface layers of steels and alloys, increases the strength of coating adhesion to the metal substrate, increases the hardness, decreases the friction factor, and increases the wear resistance of steels with chemical coatings.