Characteristics of sintered HA coating deposited by chemical method on AISI 316L substrate

Hydroxyapatite (HA) coating is widely applied for biomaterials because of its chemical similarity to the mineral component of bones. The bioactive nature of HA coating enhances the formation of strong chemical bonds with surrounding bones. The present work is aimed at investigating the effects of sintering at 500, 600 and 700 degrees C on the crystallization and adhesive properties of HA coating, deposited by chemical method on AISI 316L stainless steel substrate. The properties of HA coating were studied by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM) and standard tensile adhesion test. In addition, the corrosion behavior after heat treatments was evaluated in Ringer's solution at 37 degrees C as a simulated body fluid. The results refer to a good enhancement of the crystallization of the HA coating sintered at 700 degrees C. The adhesive strength of as-coated (AC) material increased from 8.3 MPa to 12.2, 16.8 and 19.8 MPa after sintering at 500, 600 and 700 degrees C, respectively. The corrosion rate of the as-coated material reduced sharply from 0.405 to 0.094 mu A cm(-2) after sintering at 700 degrees C. (C) 2015 Elsevier Ltd. All rights reserved.