Abstract
This work is concentrated on plasma sprayed cermet coatings consisting of stainless steel (SS) (17 wt % Cr and 12 wt % Ni) and chromium oxide (Cr2O3). These powders were sprayed simultaneously, however being injected separately to account for the drastic difference in their thermo-physical properties. Chromium oxide was injected internally and stainless steel externally. The plasma parameters (arc current, hydrogen vol %, mass flow rate) were optimized as well as the injector positions. Coatings were achieved with different mass ratios of SS and Cr2O3. All exhibited a lamellar structure with well distributed Cr2O3 and SS lamellae. They were then systematically characterized by their phase content (XRD), composition (EDS), Vickers micro hardness, morphology (SEM), slurry and dry wear resistances. Finally the best dry linear abrasion resistance was obtained for the pure chromium oxide coatings, while the best slurry wear resistance corresponded to coatings with a mass ratio SS/ Cr2O3 of 56/44.