Characterization of Hydroxyapatite Coating on 316L Stainless Steel by Sol–Gel Technique

Abstract

Biomaterials are used for developing implants and producing a part or facilitating a function of a human body in a safe, reliable, and economical manner. Sol–gel deposition is one of the best, simple and economical methods of surface modification. In the current work, hydroxyapatite Ca₁₀(PO₄)₆(OH)₂, a bioactive material, has been prepared and then deposited on 316L stainless steel by the sol-gel coating method. The porosity percentage of hydroxyapatite coating was found to be 0.22. Electrochemical corrosion testing was carried out for both uncoated and sol-gel coated specimens. The coated specimens were characterized by the X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and cross-sectional analysis. The results revealed that the Ca/P ratio of the sol-gel coated steel was closer to that of a real human bone. It was found that hydroxyapatite-coated samples show better corrosion resistance and better implant properties as compared to those of the uncoated 316L stainless steel.