What is the cause of sand sticking in sand casting?
This is because the coating does not effectively block the barrier, or the coating reacts chemically with the hot metal liquid.
1. Poor adhesion of paint: the paint peels off when the sand is shaken, causing the casting to stick sand.
2. The coating has a large expansion coefficient: when it is in contact with a high-temperature metal liquid, the coating is heated and expanded by the mold, which causes the casting to adhere to the sand.
3. The high temperature liquid metal is oxidized and chemically reacted with the coating and sand casting to form metal oxide, which has strong adhesion to the coating and the molding sand. It can firmly adhere the molding sand to the surface of the casting to form a series of low melting point compounds. [In the thick wall and corner of the casting, etc., the low melting point is more, the sanding layer is later), causing the casting to stick sand, sometimes without sticking sand, but sticking a layer of hard-to-clear coating on the surface of the sand casting casting And produce sticky ash.
