Three kinds of calcium phosphate ceramic powders, namely commercial hydroxyapatite (CHA), self-made hydroxyapatite (SMHA) and synthesized hydroxyapatite (SHA), are employed as starting materials for plasma-sprayed coating onto a stainless steel (316L) substrate. Results show a mixture of hydroxyapatite (HA), tricalcium phosphate (TCP), and tetracalcium phosphate (TeCP) phases appearing in the CHA and SHA-derived coatings and a primary of a HA with trace contents of tricalcium phosphate phases resulting in the SMHA-derived coating. The HA appears to be the only observable crystalline phase present in the SMHA-derived coating after 7 days of incubation with a simulated body fluid (SBF); however, part of the impurities, i.e. TCP and TeCP, remain in the other coatings. No apparent microcracks can be found on the coated surfaces when SMHA and SHA are used. The poor packing density of SHA reflects its weakness in bonding strength to the substrate surface compared with that obtained using CHA and SMHA powders. The surface morphology of the coatings was found to alter significantly after a sufficient period of incubation.
|Number of pages||7|
|Journal||Journal of Materials Science: Materials in Medicine|
|State||Published - 1 Mar 1994|