Aluminum Castings

N sand casting, re-usable, permanent patterns are used to make the sand moulds. The preparation and the bonding of this sand mould are the critical step and very often are the rate-controlling step of this process. Two main routes are used for bonding the sand moulds: • the "green sand" consists of mixtures of sand, clay and moisture. • the "dry sand" consists of sand and synthetic binders cured thermally or chemically. The sand cores used for forming the inside shape of hollow parts of the casting are made using dry sand components.