Development of Reinforced Nanostructured Steel Coatings

Carbide based cermets have been extensively used due to their outstanding wear properties. The high carbide contents prevent erosive and also abrasive attack as they make coatings hard. However, cermet coatings with high carbide contents become very ineffective in preventing wear by impact and the high production costs associated to the low deposition efficiency and the finishing steps used to make this technology prohibitive for large components. On this regard, nanostructured/pseudo amorphous steels represent a revolution in material science because they have strengths up to four times that of current steel and outstanding corrosion resistances. This work deals with the development of novel cost effective wear and corrosion resistant coatings based on a nanostructured/ pseudo amorphous steel matrix reinforced with tungsten carbide. As spray process, the recently introduced oxy-fuel ionisation (OFI) technology was used. The developed coatings have been characterised in terms of their sliding wear, cavitation and corrosion performance.