Fine Powder Plasma Spraying of Chromia and Alumina for High Wear Performance

Chromia and alumina are staple materials used for wear and corrosion resistant coatings across many industrial fields such as printing, pulp and paper, industrial valves to name a few. Plasma spray has been one of the main methods to manufacture dense oxide coatings for these applications. Improved properties of such coatings are achieved through increasing density and refining coating structure. This has led to a drive to reduce the ceramic powder particle size used to produce the coatings; most recently with the move to suspension based feedstocks with fine micrometric powders.

Fine powder spraying (FAPS) is an alternative method to produce high density coatings using a super fine, dry powder feedstock. FAPS can allow coatings to be produced without resorting to liquid feedstock while still achieving very high performance. This paper presents chrome oxide and aluminium oxide coatings produced using FAPS and conventional powder spraying. Coatings have been evaluated for their wear performance in order to see how FAPS compares with state-of-art dense oxide coatings.