(福州大学 材料科学与工程学院，福州 350116)
摘 要: 采用改良座滴法在真空条件下研究Au-30%Si(摩尔分数)合金与石墨在1373~1473？K温度范围内的润湿性及铺展动力学。结果表明:随着温度升高，该体系润湿性得到改善，T=1373？K时，体系终态接触角高达100°，呈不润湿；当T≥1393？K时，随着温度的升高，接触角的变化速率明显加快，接触角减小至16°，呈现良好的润湿性。界面反应产物SiC的形成使得固/液界面能不断降低，为润湿铺展提供驱动力。通过建立新的反应润湿动力学模型，从能量角度阐述润湿铺展机制，预测体系固/液界面能随反应时间的延长呈指数关系降低。在反应控制阶段，理论计算与实验结果一致。
关键字: Au-Si合金；石墨；润湿性；动力学
（College of Materials Science and Engineering, Fuzhou University, Fuzhou 350116, China）
Abstract:The wettability and spreading dynamics of Au-30%Si (mole fraction) alloys on graphite were studied using a modified sessile drop method under vacuum at 1373-1473？K. The results show that the wettability improves with the temperature increasing. The alloy is non-wetting with graphite and final contact angle as large as 100° at 1373？K. When T≥1393？K, the contact angle accelerates apparently with the temperature increasing, and finally presents an excellent wettability with contact angle decreasing to 16°. The formation of interfacial reaction products SiC resulting in the continuous decrease of solid-liquid interfacial energy, which provides the driving force for wetting and spreading. A spreading kinetic model is established, which explains the wetting mechanism from the angle of energy and predicts the solid-liquid interfacial energy decreasing with time in exponential relationship. The experimental results are in accord with the theoretical calculation in reaction-limited spreading.
Key words: Au-Si alloy; graphite; wettability; dynamics
