Development of nanostructured HVOF coatings for wear resistant application

Machinery used in mining and mineral processing industry suffers from severe degradation through abrasive wear. The current techniques used to extend the wear life of components exposed to these environments include the heat treatment of steels and the hardfacing of surfaces. However, thermal spraying techniques such as the use of High Velocity Oxy-Fuel (HVOF) composite coatings based on WC-Co system offer better wear resistance and greater flexibility in application. The ability to deposit HVOF coatings with a nano-crystalline structure provides an increase in wear resistance over that achieved using micro-crystalline coatings of the same composition. This paper reviews the application of the HVOF. Coating technique, and compares the wear resistant behaviour of a C-Mn steel substrate coated using micro and nano-crystalline W-Co coatings. (author)