Wear behaviour and microstructural characteristics of cold sprayed nickel-alumina coatings on boiler steel

Abstract

There is an excessive material loss in steel components due to sliding wear in different industrial applications. The SS 316 steel is extensively used in the power generation industry for boilers, induction fans, ducts, etc., and counter-high sliding wear. The studies have shown that protective coatings deposited by thermal spray methods successfully control the wear and enhance the service life of steels. In this work, the nickel-alumina coating was deposited on SS 316 by cold spray technique to understand the effectiveness of coatings in resisting wear. The wear behavior of coatings was analyzed by conducting the wear test on a pin-on-disc apparatus at different loads, i.e., 30, 40 and 50 N keeping the speed constant. The wear trends and variation in friction coefficient due to wear were observed. The mechanical and microstructural characterization was done by FE-SEM/EDS and XRD techniques. The coatings were found effective in resisting the wear on SS 316 steel. The results indicate that the wear rate of coatings increased with an increase in normal load.