Removing lost foam pattern coating residue from a casting

摘要

In the lost foam casting of aluminum, coating a fugitive pattern with a refractory coating containing a thermally stable, water-insoluble, acid-gasifiable (e.g. CaCO3) compound, and contacting the casting, with the coating thereon, with an acid to dissociate and gasify the compound and rupture the coating. Preferably, any thermal degradation products from the pattern residing in the coating are neutralized to promote wetting of the coating.