Investment casting refers to the process of making a fusible model using fusible materials, coating it with several layers of specially made refractory coatings, drying and hardening it to form a complete shell, then melting the model from the shell with steam or hot water, placing the shell in a sand box, filling it with dry sand around it, and finally placing the mold in a baking furnace for high-temperature calcination. After the mold or shell is calcined, Casting is obtained by pouring molten metal into it.

The products obtained by investment casting are complex and close to the final shape of the parts, and can be directly used without or with little processing. It is an advanced technology for near net formation and an excellent process technology in the casting industry, with a wide range of applications. It is not only suitable for casting various types and alloys, but also produces castings with higher dimensional accuracy and surface quality than other casting methods. Even complex, high-temperature resistant, and difficult to process castings that are difficult to cast by other casting methods can be cast using investment casting precision casting.

At present, the investment casting process in the world is developing rapidly and widely used. From the current situation, the future development trend of this process is that casting products are becoming closer to component products, and traditional precision castings are only used as blanks, which are no longer suitable for the rapid changes in the market. The complexity and quality level of component products are increasing, and research and development methods are becoming stronger. Collaboration is beginning to emerge, and the application of CAD, CAM, and CAE has become the main technology for component product development.

From the current development situation analysis, the application of investment casting technology is very extensive, and its future development prospects are expected to be broad.

(4) The impact of shell making materials: Using zircon sand, zircon powder, Shangdian sand, and Shangdian powder, due to their small coefficient of expansion, it is only 4.6 × 10-6/℃, therefore it can be ignored.

(5) The effect of shell roasting: Due to the small expansion coefficient of the shell, when the shell temperature is 1150 ℃, it is only 0.053%, so it can also be ignored.

(6) The influence of pouring temperature: The higher the pouring temperature, the greater the shrinkage rate, while the lower the pouring temperature, the smaller the shrinkage rate. Therefore, the pouring temperature should be appropriate.