(福州大學(xué) 材料科學(xué)與工程學(xué)院，福州 350116)
摘 要: 采用改良座滴法在真空條件下研究Au-30%Si(摩爾分?jǐn)?shù))合金與石墨在1373~1473？K溫度范圍內(nèi)的潤濕性及鋪展動(dòng)力學(xué)。結(jié)果表明:隨著溫度升高，該體系潤濕性得到改善，T=1373？K時(shí)，體系終態(tài)接觸角高達(dá)100°，呈不潤濕；當(dāng)T≥1393？K時(shí)，隨著溫度的升高，接觸角的變化速率明顯加快，接觸角減小至16°，呈現(xiàn)良好的潤濕性。界面反應(yīng)產(chǎn)物SiC的形成使得固/液界面能不斷降低，為潤濕鋪展提供驅(qū)動(dòng)力。通過建立新的反應(yīng)潤濕動(dòng)力學(xué)模型，從能量角度闡述潤濕鋪展機(jī)制，預(yù)測體系固/液界面能隨反應(yīng)時(shí)間的延長呈指數(shù)關(guān)系降低。在反應(yīng)控制階段，理論計(jì)算與實(shí)驗(yàn)結(jié)果一致。
關(guān)鍵字: Au-Si合金；石墨；潤濕性；動(dòng)力學(xué)
（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
