The laser deposition of stainless steel-matrix composite surfaces

Abstract

Austenitic stainless steels are alloys of iron and chromium designed to have excellent corrosion resistance. Their resistance to wear is however less remarkable, and improvements to this and to their mechanical properties are desirable. The aim of this research was to investigate the improvement of these properties by means of the laser deposition of stainless steel matrix composite layers or tracks. Tungsten carbide agglomerates, chromium carbide and alumina were selected as the reinforcing materials. A methodology was devised for improving deposition process investigation times and economy. This was then applied to the determination of deposition conditions which promoted particle survival and improved wear resistance without excessively diminishing corrosion resistance. The effectiveness of coating ceramic materials with metal in order to enhance their probability of surviving the process was evaluated using silver-coated alumina and tungsten carbide agglomerates. The outcome of the deposition process was investigated by means of characterization techniques and by wear, erosion and corrosion testing.