Wetting of Ceramics by Liquid Aluminum

Abstract

The wettability of AlN, TiB 2 , TiN, and TiC by liquid aluminum was investigated by the sessile drop technique at 2×10 ‐7 torr or less. The contact angle decreased linearly with increasing temperature in all cases. Variation of the contact angle with temperature is correlated with the surface tension of the drop, and the Zisman‐type relation is established. The critical surface tensions (Rγ c ) of AlN, TiB 2 , TiN, and TiC are 664, 700, 713, and 725 dynes/cm, respectively. These values are correlated with the melting point of the ceramics. The Zisman relation is discussed and applied to calculation of the work of adhesion. The surface tension of liquid aluminum varies linearly with temperature: γ Lv (dynes/cm) = 948–0.202 T (°K).