In order to improve the wetting ability of metal to ceramic, silica coatings on alumina/ mullite ceramics were prepared with tetraethyl orthosilicate (TEOS) by sol-gel method. The preparation processing was optimized. Furthermore, the interactions between the aluminum melt and the ceramic with or without silica coating were investigated. The results showed that the silica coatings could be successfully prepared. The molten aluminum melt reacted with silica, and alumina was formed at the interface between ceramic and metal. The ceramic (alumina/ mullite) substrates could be infiltrated by aluminum melts due to the existence of mullite. The silica coatings conduced to the infiltration and improved the combination between the ceramic and aluminum at the interface.
