Structure and Properties of Composite Coatings Based on a B83 Alloy Reinforced with Intermetallics

Abstract—The structure and properties of composite coatings, which are formed by argon-arc surfacing and are based on a B83 alloy reinforced with 3 wt % Al–Bi or Ti2NbAl intermetallic particles less than 100 μm in size are investigated. The composite coatings are found to have a fine-grained structure and a significantly higher fraction of SnSb intermetallic precipitates with cross-sectional area less than 5000 μm2, namely, 70 and 100% for Al–Bi and Ti2NbAl reinforcement, respectively. In contrast, 45% of the SnSb particles in the cast matrix alloy coating have surface area exceeding 5000 μm2. In terms of hardness and tribotechnical characteristics, the composite coatings surpass the cast B83 alloy coatings. The composite coatings reinforced with Ti2NbAl particles exhibit the best hardness (36 HB) and wear rate (3.5 mm3/m), and the coatings containing Al–Bi particles have the lowest friction coefficient (0.133).