Multifunctional bioceramic composite coatings deposited by cold spray

Bioactive coatings have predominately been explored through plasma spray; but this technique has associated heat and melting of the feedstock materials thereby degrading the novel bioactive properties of hydroxyapatite (HA), as well as deteriorating the adhesion of the coating to the implant. The current study discusses a novel approach to producing biocompatible coatings that have been deposited at temperatures well below their melting point. The cold spray process was used to deposit 100 wt.% titanium (Ti) and composite powders with 80 wt% titanium (Ti) and 20 wt% hydroxyapatite (HA) onto Al6061, 316SS and Ti-6Al-4V substrates with the aim of achieving well-bonded homogeneous coatings; the effect of process parameters and substrate material was investigated. Preliminary results indicate the phase composition of the HA remained the same before and after synthesis of coating. Dense composite coatings were obtained with thicker coatings yielding the least amount of total porosity.