Metal mold casting and die casting, it is the liquid metal is poured into the mold for casting, a casting method. The mold is made of metal, can be repeatedly used for many times ( hundreds to thousands of times ).
The metal to the casting and sand casting: comparison on technology and economy has many advantages.
( 1) metal production casting, its mechanical properties than sand casting high. The same alloy, its tensile strength can be increased by about 25% on average, yield strength improved an average of about 20%, its corrosion resistance and hardness increase evidently;
( 2) the casting precision and surface smoothness than sand casting, but also the quality and dimensional stability;
( 3) the casting process has high yield, liquid metal consumption is reduced, the general can save 15～ 30%;
( 4) without sand or less sand, general can save 80～ 100% modeling materials;
In addition, metal casting the production efficiency is high; the casting defects is reduced; has the advantages of simple process, easy realization of mechanization and automation. Metal mold casting has many advantages, but there are also shortcomings. Such as:
( 1) metal type high manufacturing cost;
( 2) metal type airtight, and no concessions, easy washing, cracking or insufficient casting defects such as cast iron pipe;
( 3) metal mold casting, casting temperature, pouring temperature and casting alloy casting speed, casting in time to stay, as well as the coating on the quality of castings, the influence is very sensitive, the need for strict control.
Metal mold casting at present can produce castings, in weight and shape has some limitations, such as the black metal only is the simple shape castings; castings weight should not be too big; the wall thickness is restricted, the smaller thickness of the casting to cast. Therefore, the decision to adopt metal mold casting, must consider the following factors: casting shape and weight size must be suitable; to have enough volume of production tasks to complete the term of the license.