为了减少激光熔覆过程中基材与生物陶瓷涂层之间的热应力,提高涂层与基材的结合强度,设计了一种稀土活性生物梯度陶瓷涂层,采用宽带激光熔覆技术,在TC4合金上制备了含HA+β-TCP稀土活性梯度生物陶瓷复合涂层。利用扫描电镜(SEM)、X射线衍射(XRD)、模拟体液(SBF)以及电化学分析仪等手段对涂层组织结构、生物活性及耐腐蚀性进行了研究。结果表明,生物活性稀土梯度涂层分为基材、合金化层以及生物陶瓷层3个层次,且各梯度层之间均为良好的化学冶金结合;稀土氧化物Nd2O3在宽带激光熔覆生物陶瓷的过程中具有催化合成HA+β—TCP的作用,且当Nd2O3质量分数为0.6%时,催化合成HA+β-TCP的量最多;当Nd2O3质量分数为0.4%~0.6%时,涂层的耐腐蚀性最好且涂层表面沉积的磷灰石相的量最多,具有最佳的生物活性。
To decrease the thermal stress during laser cladding, a rare earth active and raise the bonding strength between bioceramic gradient coating is designed substrate and bioceramic coating The rare earth active gradient bioceramic coating with HA and β-TCP on TC4 allloy is prepared by using wide-band laser cladding technique. The microstructure, bioactivity and corrosion resistance of bioceramic coating are analyzed by scanning electron microscope (SEM), X-ray diffraction (XRD), simulated body fluid (SBF), and electrochemical analyzer. The experimental results show that the bioactive rare earth gradient coating which has excellent chemical metallurgy bonding at the interface consists of substrate, alloying layer and bioceramic coating. Nd2 O3 plays an important role in synthesizing HA and β-TCP during wide-band laser cladding. When the mass fraction of Nd2O3 is up to 0.6%, the amount of HA+ ~-TCP catalyzed during wide-band laser cladding becomes the largest. When the mass fraction of Nd203 is 0. 4% - 0. 6%, the corrosion resistance of bioceramic coating is the best one, and the amount of HA deposited on coating becomes the biggest, showing the best bioactivity.