钛合金微弧氧化医用涂层形成机制

摘要

Medical coatings on titanium alloy surface were prepared by micro-arc oxidation（MAO）.The morphology characteristics of coatings at different oxidation stages were observed by scanning electron microscopy（SEM）.The micro-arc discharge characteristics and electrochemical reaction of the two electrods were studied.The equivalent circuit of electrolyte load was established and analyzed.The hydroxyl-apatite（HA） coating formation mechanism of MAO was proposed.The results showed that the voltage could affect the charge distribution on specimen surface directly.The charge accumulation was enhanced,and the diffusion and electrophoresis degree of Ca2＋and PO43-increased in electrolyte,which accelerated the instant reaction for the substances in coating.%利用微弧氧化技术在钛合金表面制备了医用涂层,通过SEM观测不同氧化阶段涂层形貌,并分析各阶段微弧放电特性。研究了两极电化学反应过程,建立了工作液负载等效电路,提出了钛合金微弧氧化生成羟基磷灰石医用陶瓷涂层机制。结果表明,电压会直接决定试样表面的电荷分布,增加表面电荷积累,增强工作液中带电钙、磷粒子的扩散和电泳程度,从而加速涂层物质的瞬间反应。