EFFECT OF THE STRUCTURE OF TiB2–(Fe–Mo) PLASMA COATINGS ON MECHANICAL AND TRIBOTECHNICAL PROPERTIES

Abstract

The structure, mechanical properties, and wear-resistance of TiB2–(Fe–Mo) plasma coatings are investigated. Composite powders in the TiB2–(Fe–Mo) system with 20, 40, 60, and 80 wt.% of the Fe–13 wt.% Mo alloy were produced by vacuum sintering with subsequent grinding. The developed powders are conglomerates that contain both refractory and metallic phases. During plasma spraying of developed coatings, a coating with heterophase structure, which consists of Fe-based metal alloy and titanium diboride grains, is formed. The effect of the microstructure of plasma-sprayed coatings on the wear-resistance under abrasive wear and dry sliding friction conditions is studied. The scratch hardness testing revealed an insufficient strength of TiB2–20 wt.% (Fe–13 wt.% Mo) coatings and their poor adhesion to the coating base, resulting in the extremely gross wear, when friction. It is found out that, due to the optimal ratio of refractory and metallic phases, the TiB2–40 wt.% (Fe–13 wt.% Mo) coating possesses high wear-resistance under abrasive wear and dry sliding friction conditions.