Precision casting is a kind of technology. There are many forms of technology used in precision casting. Precision casting process includes pressure casting, metal mold casting, ceramic mold casting and investment casting, etc. precision casting process is diversified.
Different process requirements require different precision casting processes, and precision casting is a process. When choosing the precision casting process in real life, the process form of precision casting process should be selected according to its specific requirements.
Treatment of pores during precision casting:
Gas does not escape in time before liquid metal crusting, resulting in holes and defects in castings. The inner wall of pores is smooth, bright or with slight oxidation color. The effective bearing area of the casting will be reduced when there are pores in the casting, and stress concentration will be caused around the pores, which will reduce the impact resistance and fatigue resistance of the casting. Porosity also reduces the compactness of castings, resulting in the scrapping of some castings requiring hydrostatic test. In addition, porosity also has a bad effect on the corrosion resistance and heat resistance of castings.
Prevent the generation of pores: reduce the air content in the molten metal, increase the air permeability of the sand mold, and add an air outlet riser at the highest part of the mold cavity.