Cobalt based alloy thick coatings by CDS process

Abstract

The continuous detonation spray (CDS) process is one of the most recently developed coating processes andallows the production of thick coatings. This paper examines the correlation between process parameters and the properties of WC–17Co coatings deposited by CDS on an austenitic stainless steel substrate. Among the parameters considered the most important are the oxygen and propane flowrates and the ratio between them, and the distance between the torch nozzle and the surface to be coated. The first three affect the amount of process heat generated, while the last affects the interaction between the flame and the sprayed powders, determining the heating rate and final temperature. Coatings were evaluated in terms of porosity, surface roughness, hardness, and wear resistance.