Tribological properties of plasma and HVOF-sprayed NiCrBSi–Fe2O3 composite coatings

This paper presents the properties of plasma and HVOF thermally sprayed coatings obtained by blending the NiCrBSi and Fe2O3 powders. Although the blended powders differ in particle size, shape, and distribution, it is possible to obtain composite coatings with a NiCrBSi matrix containing iron oxides. Except for a different microstructure, plasma and HVOF coatings have a different phase composition. An addition of Fe2O3 powder in the mixture with NiCrBSi powder led to a significant increase in roughness of the coating sprayed both in a plasma and supersonic manner. The coefficient of friction, microhardness and roughness of the coatings was determined using an experimental design called PS/DS-P:24 − 1 program. The study shows that the HVOF-sprayed coatings had a lower coefficient of friction.

► Effect of plasma and HVOF spraying powder mixtures of different sizes were presented. ► The final optimized processing parameters were selected by DOE. ► Influence of spraying parameters on COF, microhardness and roughness of coatings was discussed.