Investigation on corrosion behaviour of HAp coating on biomaterial

Metallic biomaterials have been commonly utilized in the manufacturing of implants owing to their superior mechanical properties and economic aspects that fulfil the prerequisite of the human bone. But, metallic implants have some issues; that consist of releasing harmful metal ions through corrosion & wear processes after longer type implantation. In addition, the failure of the orthopaedic implant after implantation occurs commonly due to many reasons such as least corrosion resistance, stress shielding, mismatch in elastic modulus, inflammatory response and excessive wear. To overcome these issues, distinct modifications related to materials, design and surface have been developed. Among the distinct modification methods, the coating is an effective way to enhance the performance of orthopaedic implant materials. Hence, in the current investigation, flame-sprayed hydroxyapatite bioactive coating was deposited on the most widely used biomaterial (316 L stainless steel) to improve their biocompatibility and resistance against corrosion. Further, the in-vitro corrosion performance of uncoated and flame-sprayed hydroxyapatite (HAp) coated 316L SS sample was evaluated in simulated human body fluid. The microstructural morphology of test samples (bare and coated) was analyzed by SEM. The tests were completed for “open circuit potential” and “potential-dynamic polarization”. The resistance against corrosion of the steel substrate was observed to increase after the deposition of HAp coating.