Microstructures and Properties of Cold Spray Nanostructured HA Coatings

摘要

Nanostructured hydroxyapatite (nHA) coatings on implant surface are highly desirable owing to their excellent osteoconductive properties in association with intrinsic small crystals. Low processing temperature of cold spray makes it an ideal technique to prepare nHA coatings with nanostructured feedstock. This work demonstrated that dense and thick nHA coatings were achievable by cold spraying nanostructured feedstock onto TC4 alloy surface. Coating formation mechanisms were explored by investigating the deposition of individual particles. Microstructures, mechanical profiles and biological properties of the coatings were comprehensively investigated. A porous Ti buffer layer significantly enhanced the bonding between nHA coatings and the substrate. As-deposited nHA coatings exhibited a high wear resistance when slid against polyurethane or polycarbonate and a strong apatite-forming ability when being immersed in simulated body fluid (SBF). Findings of this work will contribute to a comprehensive understanding of building mechanisms, structures and properties of cold sprayed nHA coatings.