Comparison of permanent mold casting and sand casting: There are many advantages in technology and economy.
(1) Permanent mold casting have higher mechanical properties than sand castings. For the same alloy, the average tensile strength can be increased by about 25%, the yield strength can be increased by about 20%, and its corrosion resistance and hardness have been significantly improved;
(2) The precision and surface finish of castings are higher than those of sand castings, and the quality and size are stable;
(3) The process yield of the casting is high, and the consumption of liquid metal is reduced, which can generally save 15-30%;
(4) No sand or less sand is used, which can generally save 80 to 100% of the molding material;
In addition, the production efficiency of metal mold casting is high; the causes of defects in castings are reduced; the process is simple, and it is easy to realize mechanization and automation