钛表面等离子体电解氧化制备的Ca-P-Si生物活性陶瓷膜的电化学性能

采用等离子体电解氧化法在钛表面制备Ca-P-Si生物活性陶瓷氧化膜。将纯钛及等离子体电解氧化后纯钛两种样品分别浸在37℃的Hank模拟体液中,用电化学实验分析其电化学性能。动电位极化曲线和交流阻抗结果表明,经过等离子体电解氧化处理后纯钛的自腐蚀电位升高了0.7V,经过28d的浸泡,微弧氧化处理后钛的阻抗值仍接近未处理时的1.5倍。微孤氧化陶瓷膜提高钛基体耐腐蚀性能归因于外层的羟基磷灰石层及微弧氧化的致密内层形成隔离层将基体与溶液隔离,起到了抗腐蚀作用。

Electrochemical Performance of a Novel Ca-P-Si Bioactive Ceramic Coating Formed on Titanium Surface by Plasma Electrolytic Oxidation

The Ca-P-Si bioactive ceramic coating was prepared by means of plasma electrolytic oxidation on the surface of pure titanium.The sample surface was almost completely covered by hydroxyapatite after being immersed in simulated body fluid in 28 days.The electrochemical performances of pure titanium and plasma electrolytic oxidized (i.e.bioactive ceramic coated) pure tita-nium, both of which were immersed into Hank's simulated body fluid at 37 ℃, were analyzed by electrochemical experiment.The results of the potentiodynamic polarization curves and the alternating-current impedance showed that the Ca-P-Si coated sample achieved an Ecorr rise of 0.7 V compared to pure Ti, as well as an impedance conspicuously higher than pure Ti after 28 days immersion.The corrosion resistance of the Ti matrix is promoted after Ca-P-Si coating due to an isolating layer composed of hydroxyapatite outer layer and compact micro-arc oxidized inner layer, which protects the substrate from solution corrosion.