Influence of Spraying Distance on Phase Composition and Electronic Property of Plasma Boron Carbide Coating
等离子喷涂碳化硼涂层相组成和电学性能研究

Boron carbide coatingS were deposited under atmospheric pressure by plasma spray at differentspraying distance. Their microstructure and phase composition were studied through EPMA, EDSand XPS. Their dc conductivity was measured by standard four-probe. The results show that thesuitable spraying distance causes dense B4C coating; the longer the spraying distance, the seriousoxidation of B4C powder is, the spraying distance may severely effect the phase composition. Theplasma spray boron carbide coatings possess semiconductor properies. The conductivity increaseswith temperature. The phase composition and B/C ratio determined by the spraying distance,can effect the conductivity of boron carbide coating.