Wetting of Sn on Al-steel multilayered composite plate at 350-450 °C

Abstract

Wetting of Al-steel multilayered composite plate by molten Sn was studied under high vacuum at 350-450 °C. Dissolution and reaction for liquid/Al interface and liquid/steel interface, respectively, induced the spreading. As a layered interface, the anisotropic wetting happened due to the physical and chemical heterogeneities. Three models, the classic Cassie model, the modified Cassie model with the consideration of Wenzel model or the local contact angles, were failed to fit the final contact angles. A modified Naidich’s model, also based on Cassie model, together with the consideration of metallurgical segregation, fits the results. Comparing to thermodynamic conditions of reaction and dissolution, the precipitation of reaction product is easier. Also, considering the wetting activation energies (almost the same in Sn/Al-steel multilayered composite and Sn/Al), we believed that the spreading may be limited by the dissolution of Al into liquid or the diffusion of Al in liquid.