The characteristics of the metal mold casting forming process

The characteristics of the metal mold casting forming process
Sand mold and metal mold, has a significant difference in performance, such as sand permeability, but not for metal mold; The thermal conductivity of the sand mold, metal mold has a good thermal conductivity, sand mold have rolled back, and metal mold is not, and so on. These characteristics of metal mold determines its formed in the casting process has its own rule.
Inside the cavity gas change of state effect on casting molding, metal when packing, the gas must be within the cavity discharge rapidly, but metal and have no permeability, as long as a little carelessness on process, will bring the quality of the castings.
Liquid metal casting during solidification heat exchange features: once in the cavity, the heat to the metal mold wall. Type of liquid metal through the wall heat loss, carries on the solidification and contraction, and obtain heat type wall in, the expansion of the higher temperature at the same time, the results between the casting and the type of wall formed a "clearance". In "a metal mold casting a clearance" system fails to reach the same temperature, before the casting can be regarded as cooling in the "gap", while type metal wall through "clearance" is heated.