钛硅铝锡复合涂层对钛/瓷结合的影响

Effect of TiO_2-SiO_2-Al_2O_3-SnO Composite Coatings on the Bonding Strength of Ti-Porcelain

研究了钛硅铝锡四元复合涂层作为扩散阻挡层对钛/瓷结合强度的影响。通过测量复合溶胶的粘度对溶胶的稳定性进行评价,并进一步优选出与纯钛热膨胀系数匹配的复合溶胶的成分。采用电化学工作站对涂层处理后钛试样在人工唾液中的耐腐蚀性能进行评价,研究了涂层处理对钛试样耐腐蚀性能的影响。结果表明:复合溶胶中SiO2溶胶含量对溶胶粘度的影响较大,SiO2含量较高时复合溶胶粘度上升较快,凝胶时间较短,溶胶稳定性较差。n(Ti):n(Si):n(Al):n(Sn)=3:1:1:3的复合溶胶的热膨胀系数为9.28×10-6/℃,与钛的热膨胀系数相匹配。300℃处理获得的复合涂层主晶相为SnO,同时涂层表面存在较多的微米级的裂纹。涂层处理可明显提高钛的耐腐蚀性,中性与中性含氟人工唾液浸泡对钛/瓷结合强度没有明显影响。而pH=3/[F-]=1×10-4的人工唾液对钛的腐蚀最严重,浸泡30 d后,钛/瓷结合强度由浸泡前的45 MPa下降到35 MPa。

The TiO2-SiO2-Al2O3-SnO composite coating was deposited on titanium as oxygen diffusion barrier by sol-gel dipping process. The adhesion between the Ti and porcelain was evaluated. The stability of the sols was characterized by the variation of viscosity with time at room temperature. The thermal expansion coefficients of the coatings were modulated by changing the composition of the sols to match the thermal expansion coefficient of Ti. The main phase of the gels treated at 300 °C is SnO. The SEM results reveal the existence of microcracks on the composite coating surface after being treated at 300 °C. The composite coating enhances the corrosion resistance of the titanium. After being immersed in artificial saliva with pH of 6.8 and pH 6.8/[F-]=1×10-4, no decrease of the bonding strength of Ti-porcelain occurs. However, the bonding strength of Ti-porcelain decreases from 45 MPa to 35 MPa after being immersed in artificial saliva with pH=3/[F-]=1×10-4.