宽带激光熔覆梯度稀土生物陶瓷涂层的生物活性

为了减少激光熔覆过程中基材与生物陶瓷涂层之间的热裂纹, 提高涂层与基材的结合强度, 设计了一种梯度稀土生物陶瓷涂层, 采用宽带激光熔覆技术,在TC4钛合金表面制备了含HA＋β－TCP活性相的稀土活性梯度生物陶瓷复合涂层。利用SEM 、XRD分析手段对涂层形貌、相组成进行了研究; 通过模拟体液(SBF)浸泡实验(浸泡7 、14 d)考察了生物陶瓷涂层的生物活性; 利用电化学分析仪测试了生物活性陶瓷涂层的耐腐蚀性。结果表明, 当稀土氧化物Nd2O3添加量为w(Nd2O3)＝0.6%时, 宽带激光熔覆过程中催化合成HA＋β－TCP活性相的数量最多, 具有优异的表面形貌; 当稀土氧化物Nd2O3添加量为w(Nd2O3)＝0.6%时, 梯度稀土生物陶瓷涂层在SBF中浸泡不同时间点后表面沉积的类骨磷灰石相数量均较未加入Nd2O3的梯度生物陶瓷涂层多, 具有最好的生物活性, 且耐腐蚀性最佳。

Bioactivity of Gradient Rare Earths Bioceramic Coating Produced by Wide-Band Laser Cladding

To decrease thermal crack and to raise bonding strength between substrate and bioceramic coating during laser cladding, a kind of gradient rare earths bioceramics coating is designed. And the rare earth active gradient bioceramic coating with HA and β-TCP on Ti allloy was prepared by using wide-band laser cladding technique. The surface morphologies and microstructure were analyzed by OM, SEM and XRD; the bioceramic coating was immersed in SBF to examine its bioactivity ; and the corrosion resistance of bioceramic was examed by the Electrochemical Analyzer. Results show that the rare earth active bioceramic gradient coatings which have excellent chemical metallurgy bonding at the interface consists of substrate, alloying layer and bioceramic coating. When content of Nd2O3 is up to 0.6wt.%, the amount of HA＋β－TCP catalyzed during wide-band laser cladding becomes largest. Bioactivity and corrosion resistance of bioceramic coating is dependent on the amount of HA＋β－TCP catalyzed. The largest amount of apatite formed on the surface of gradient bioceramic coating is complied with 0.6wt.% Nd2O3. At the same time, the corrosion resistence is best.