Effect of SiC Particle Contents and Size on the Microstructure and Dissolution of SiC-Hydroxyapatite Coatings

Carbon/carbon composites, when used as bone implant materials, do not adhere well to the bone tissues because of their non-bioactive characteristics. Therefore, we electro-deposited SiC-hydroxyapatite coatings (with an ultrasound-assisted step) on carbon/carbon composites. We analyzed how the content and size of the SiC particles affected the structure, morphology, bonding strength and dissolution of the SiC-hydroxyapatite coatings. The hydroxyapatite coating dissolution properties were assessed by the released Ca2+ and the weight loss. The SiC-hydroxyapatite coating on naked carbon/carbon composites showed a more compact microstructure in comparison to the hydroxyapatite coating on carbon/carbon composites. The reasons for the changes in the microstructure and the improvement in the adhesion of the coatings on C/C were discussed. Moreover, the addition of SiC particles increased the binding strengths of the hydroxyapatite coating on C/C composite, as well as reduced the dissolution rate of the hydroxyapatite coating.