Alumina-fluorapatite composite coating deposited by atmospheric plasma spraying: An agent of cohesion between bone and prostheses.

In order to remedy the poor biological and tribological properties of 316L stainless steel (SS), plasma sprayed bio-ceramic coatings have been widely investigated. In the present study, a small amount of fluorapatite (Fap) was introduced into alumina in order to enhance its bioactivity. The powder feedstock was sprayed on 316L substrate by Atmospheric Plasma Spraying (APS) technology. The roughness profiles and average roughness values were determined using 3D profilometry. The cross sectional morphologies of the coatings were examined by scanning electron microscopy (SEM). Adhesive strength, micro-hardness and tribological properties were also examined. Experimental results revealed that Al2O3/Fap coating showed a good microhardness property revealing that the calcium aluminates were quite effective in improving the Fap mechanical behavior. The tribological characteristics of both alumina and alumina-Fap coating were also compared to those of classical hydroxyapatite (Hap) coatings as reported in the literature. The main finding of this work was that Fap coating can contribute to the cohesion between bone and prostheses and thus ensure a more durable and reliable prostheses.