Alloy coating method

TL;DR: In this paper, a method of coating a metal substrate with a ternary or greater alloy of aredetermined composition is disclosed, where a first and second metal are electrodeposited on the substrate using an aqueous electrolyte.

Abstract: A method of coating a metal substrate with a ternary or greater alloy of aredetermined composition is disclosed. Initially, a first and second metals are electrodeposited on the substrate using an aqueous electrolyte. At least one metal powder is simultaneously mixed in the electrolyte as the first and second metals are electrodeposited so that a portion of the metal powder is occluded in the electrodeposited metal coating. The rate of occlusion of the metal powder is controlled by the volume percent of the metal powder in the electrolyte. Finally, the metal coating and substrate are heat treated to diffuse the occluded metal powder in the coating and to form the desired alloy coating. A plurality of metal powders can be mixed in the electrolyte according to the present method. In addition, a diffusion barrier coating can be initially provided on the metal substrate. The method is particularly useful with iron-based metals such as stainless steel. The rate of occlusion of the metal powder is additionally controlled for iron-based metals using an iron-nickel plating solution by controlling the presence of reducible ferrous ions. The microstructure of the electrodeposited coating also affects the occlusion rate. The rate of occlusion was also increased by varying the current density.