Y_2O_3-CeO_2稀土氧化物对激光熔覆生物陶瓷涂层中HA的影响

Effect of Rare Earth Oxide Y_2O_3-CeO_2 on HA in Laser Cladding Bioceramic Coating

为降低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,选用宽带激光熔覆方法,在TC4合金表面制备一层含HA和β-TCP的梯度活性生物陶瓷涂层。通过金相显微镜、扫描电子显微镜(SEM)和X射线衍射仪(XRD)对在体外模拟体液中浸泡14d后的涂层进行形貌和相组成的研究。结果表明:当Y2O3质量分数为0.6%,CeO2质量分数分别为0%,0.2%,0.4%和0.6%时,生物陶瓷涂层在SBF中浸泡14d后,基材与涂层之间呈良好的冶金结合;涂层表面都有白色球状颗粒生成;且涂层当中HA的生成量各不相同。当CeO2质量分数为0%时几乎不生成HA,为0.2%时HA的生成量最大,而后随着CeO2的含量增加HA生成量减少。说明当Y2O3质量分数为0.6%,CeO2的含量为0.2%时,生物陶瓷涂层具有较好的生物活性。

To reduce the thermal stress between the substrate and the bioceramic coating and improve the bonding strength of the coating and the substrate during the laser cladding process,agradient of bioceramic coating with HA andβ-TCP was prepared on the surface of TC4alloy by using broadband laser cladding method in the experiment.The coating morphologies and phase structural were studied by metallographic microscope,scanning electron microscope（SEM）and X-ray diffraction（XRD）.When the mass fraction of Y2O3is0.6%,and the mass fraction of CeO2is set to 0%,0.2%,0.4%,and 0.6%,bioceramic coating with different rare earth contents after soaked in SBF 14days show a good metallurgical bond between the substrate and the coating;white spherical particles from on the surface of the coating;and the formation of HA in coatings is different,and almost no HA at the content of 0%.With the mass fraction of CeO2up to 0.2%,the formation of HA reached the maximum.However,when the content of CeO2is 0.4%,the formation goes down gradually,and becomes the lowest at 0.6%.That is to say,when the mass fraction of Y2O3is 0.6%,CeO2is 0.2%,the bioceramic coating having agood bioactivity.