Evaluation of Zn doped Hydroxyapatite Plasma Spray Biocompatible Coatings on Metallic Substrates

摘要

The lattice constants of HAp changed with the change of the ZnO/HAp ratio. Zn doped HAp plasma spray coatings on Ti and SUS316L stainless steel were prepared with Zn doped HAp powder. The evaluation of long-term credibility for Zn doped HAp plasma spray coatings on SUS316L stainless steel was conducted by electrochemical impedance measurements. The impedance results showed that Zn doped HAp plasma spray coatings have excellent corrosion resistance. It was also found that post heat treatment improved the stability of Zn doped HAp coatings on SUS316L stainless steel. The results obtained from ICP analysis also proved the higher stability achieved by post heat treatment. The dissolution of Zn~(2+) ions was confirmed, implying the possibility of stimulation to bone growth. The adhesion tests showed that Zn doped HAp coatings have strong adhesion to the metallic substrates. The residual stress in coatings was investigated by X-ray diffraction.