Abstract
The wetting of (0112) α-Al2O3 single crystals by Al-Si alloys in the full composition range was studied by an improved sessile drop method in a reducing Ar-3%H2 atmosphere at 1723 K. The wettability and the adhesion are significantly enhanced when a small amount of Al is added to Si. In turn, the effect is less pronounced when Si is added to Al. Based on the Gibbs adsorption isotherm equation and a statistic thermodynamic model, the adsorptions of Si and Al at the liquid surface and the solid-liquid interface were determined, and the experimental results were explained by the fact that Si is a surface tensioactive element while Al is an interface tensioactive element in the Al-Si/(0112) α-Al2O3 system.
