Study on Plasma Sprayed HA/Ti Composite Coatings I. Microstructure, phase composition and mechanical properties

HA/Ti composite coatings on Ti-6Al-4V substrate were successfully deposited via plasma spraying, and then the microstructure, phase composition and mechanical properties were investigated. The results obtained indicate that the phases of HA and Ti are well-distributed in the composite coatings. The bonding strengthes of HA/Ti composite coatings are much higher than that of HA coating, that is explained in terms of the reduction of the mismatch of thermal expansion coefficients between coating and substrate. The value of bonding strength of HA/Ti composite coating does not obviously vary with the immersion time in simulated body fluid. Fracture toughness and hardness of HA/Ti composite coatings are higher than that of HA coating.