Comparison between metal mold casting and sand mold casting: There are many advantages in chemical pump casting technology and economy. (1) The mechanical properties of castings produced by metal molds are higher than those of sand molds. The same alloy can increase its tensile strength by an average of about 25%, yield strength by an average of about 20%, and its corrosion resistance and hardness are also significantly improved;
(2) The precision and surface smoothness of castings are higher than those of sand castings, and the quality and size are stable;
(3) The process yield of castings is high, and the consumption of liquid metal is reduced, generally saving 15-30%:
(4) Not using sand or using less sand can generally save 80-100% of styling materials;
In addition, the production efficiency of metal mold casting is high, which reduces the causes of defects in castings, simplifies the process, and facilitates mechanization and automation. Although metal mold casting has many advantages, there are also shortcomings. For example:
(1) High manufacturing cost of metal molds:
(2) Metal molds are not breathable and have no yielding properties, which can easily cause defects such as insufficient casting, cracking, or self opening of cast iron parts:
(3) During metal mold casting, the working temperature of the mold, the pouring temperature and speed of the alloy, the time the casting stays in the mold, and the coating used are all sensitive factors that affect the quality of the casting and require strict control.
Therefore, when deciding to use metal mold casting, the following factors must be comprehensively considered: the shape and weight of the casting must be consistent, there must be sufficient batches, and the deadline for completing production tasks is allowed