Ti对Sn-xTi/Al2O3润湿性的影响

针对添加活性元素Ti有利于改善金属/Al₂O₃体系的润湿性、但润湿机制仍不明确问题,研究采用改良座滴法,研究了熔融Sn-(原子分数为0%、2%、5%)Ti合金在973~1 273 K高真空中在Al₂O₃表面的润湿性.研究结果表明:Ti原子分数的增加会显著改善Sn-xTi/Al₂O₃体系的润湿性,润湿性改善的原因在于Ti在界面处的吸附降低了固/液界面自由能,而并非界面析出的反应产物.对此结论,应用吸附的统计热力学模型验证了实验结果,并证明Sn-xTi/Al₂O₃体系的铺展动力学在很大程度上受控于吸附动力学.

Effect of Sn-xTi/Al2O3 wettability with Ti addition

In order to solve a problem that addition of active element Ti is beneficial to improve wettability of metal/Al₂O₃ system, but the wettability mechanism is still unclear, the wettability of molten Sn-(0%,2%,5%) Ti alloy on Al₂O₃ surface in high vacuum at 973~1 273 K was studied by improved sessile drop method. The results show that increase of Ti content significantly improves the wettability ofSn-xTi/Al₂O₃ system. The reason for wettability improvement is that the adsorption of Ti at the interface reduces free energy of the solid/liquid interface, rather than the reaction product precipitated at the interface. For this conclusion, conducted experimental results are verified by a statistical thermodynamic model of adsorption, and it is proved that the spreading kinetics of Sn-xTi Al₂O₃ system is well controlled by the adsorption kinetics to a great extent.