The Sodium silicate casting part process also called precision investment casting process. It is a less cutting or no cutting casting process. It is an excellent technique in foundry industry. Its application is very extensive. It not only applicable to various types, various kinds of alloy and casting, and produce the casting dimension accuracy and surface quality is higher than other casting method, Even other casting method can not do the complex, high temperature resistant, not easy machining castings, all can be used for investment precision casting process.  

The investment casting process, it is a process that use fusible materials make soluble model, and coated with several layers of tailor-made refractory coating on the surface, after drying and hardening become a whole shell, melt the shell model by steam or hot water. Then put the shells in the sand, filling dry sand in all round and modeling. Finally roasting it based on high-temperature in the furnace, the shell after roasting, and getting the casting part after pouring molten metal.  

The investment casting process can produce High precision dimensional parts, generally can reach to CT4-6(sand casting is CT10-13, die casting is CT5-7). Due to the complexity of investment casting process, there are many factors influencing the casting dimension accuracy. Such as shrinkage of mold material, deformation of the casting, Shell heating and cooling line quantity change in the process, alloy shrinkage and deformation of castings in the solidification process. The surface finish of investment castings is higher than the ordinary casting, can reach to Ra1.6~3.2.