The silica sol also shares the name of water glass in general, it is used by the meatal casting process as mold adhesive which is mixed with sand and several other materials. The silica sol is applied to both sand casting and investment casting technics. It is one of the most common investment casting processes. As the molding material, silica sol is able to stand temperature up to 1800℃. Similar to other investment casting processes, the silica sol investment casting process mainly consisted of wax injection, assembly, shell preparation, dewax, pouring, cut-off, and finished casting, etc. less