Room and elevated temperature sliding wear of high velocity oxy-fuel sprayed Diamalloy3001 coatings

CoMoCrSi alloys exhibit high hardness and excellent wear resistance due to the presence of intermetallic Laves phases in a metallic Co-matrix. In this study, we deposited Diamalloy3001 coatings using high velocity oxy-fuel (HVOF) spraying process and evaluated their tribology at temperatures 25 degrees C, 200 degrees C and 350 degrees C. At room temperature, formation of tribolayers composed of oxides of Co, Cr, and Mo resisted localized shear deformation and resulted in low wear rates. At elevated temperatures, detachment of the tribolayers, and formation of cavities during reciprocating sliding resulted in high wear rates. Electron channel contrast imaging (ECCI) of the worn subsurface showed that at elevated temperatures, oxidation of splat boundaries led to interparticle debonding during wear and decreased the stability of the tribolayers.