A Summary of Recent Developments of HVOF Sprayed Ceramic-Metallic Coatings for Corrosion and Wear Resistance

Abstract

Abstract In recent years Norwegian industries together with SINTEF and NTNU have run several projects dealing with development of thermally sprayed ceramic-metallic coatings for corrosion and wear applications. The mechanisms of erosion, corrosion and combined actions have been studied. The coatings studied are of the metal-carbide / metallic binder type sprayed by the High Velocity Oxygen Fuel (HVOF) process. The influence of powder properties like carbide particle size, powder grain size distribution, chemical composition (i.e. type of carbide and composition of the metallic binder) together with the influence of spray systems and parameters have been studied. The studies have demonstrated how optimization of powder and spray parameters improve corrosion and wear behavior of the coatings. Attention has also been paid to methods used for manufacturing powders for thermal spraying. This is very important from a corrosion point of view. The manufacturing methods should make sure that metallic binders are sufficiently alloyed to achieve the necessary corrosion resistance. The results from the work done in these projects are valuable for suppliers of thermal spray powders, spray companies and end users of coatings.