Investment casting is a casting method relative to the traditional casting process

Investment casting is a casting method relative to the traditional casting process. It can obtain relatively accurate shape and high casting precision. A common practice is to first make the electrode of the required blank (with very little or no allowance), and then use the electrode to etch the mold to form a cavity. The original wax mold is obtained by casting wax. Brush high temperature resistant liquid sand on the wax mold layer by layer. After sufficient thickness is obtained, it is dried, and then heated to melt the internal wax mold, so as to obtain a cavity consistent with the required blank. Then, molten iron is cast in the mold cavity, and the shell is peeled off after solidification to obtain precision manufactured products.


Wax loss casting is now called investment casting, which is a kind of casting process with little or no cutting, and is an excellent process technology in the casting industry. It is widely used. It is not only applicable to the casting of 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 by investment casting.


The practical application of modern investment casting method in industrial production was in the 1940s. At that time, the development of aerojet engines required the manufacture of heat-resistant alloy parts with complex shapes, accurate dimensions and smooth surfaces, such as blades, impellers and nozzles. Because heat-resistant alloy materials are difficult to machine and parts are complex in shape, so it is impossible or difficult to manufacture them by other methods. Therefore, it is necessary to look for a new precision forming process. Therefore, it is necessary to learn from the lost wax casting handed down in ancient times. Through the improvement of materials and processes, modern investment casting methods have achieved important development on the basis of ancient processes. Therefore, the development of aviation industry promotes the application of investment casting, and the continuous improvement and perfection of investment casting also create favorable conditions for the aviation industry to further improve its performance.


Investment casting was applied to industrial production in China in the 1950s and 1960s. Since then, this advanced casting process has been greatly developed, and has been widely used in aviation, automobiles, machine tools, ships, internal combustion engines, steam turbines, telecommunications instruments, weapons, medical equipment, tools and other manufacturing industries, as well as in the manufacture of arts and crafts.


Another advantage of investment casting method is that it can cast complex castings of various alloys, especially superalloy castings. For example, the blade of a jet engine, with its streamlined profile and cooling cavity, can hardly be formed by machining. The investment casting process can not only achieve batch production, ensure the consistency of castings, but also avoid the stress concentration of residual knife lines after machining.


The sprue cup is a basic component serving the casting technology, especially closely related to the development of the steel industry. The sprue cup is one of the components of smelting process equipment.


The sprue cup is mainly used to guide the passage of liquid metal into the mold cavity. If the runner cup is arranged unreasonably, the casting may have defects such as air hole, sand hole, iron bean, slag hole, shrinkage cavity, crack and insufficient pouring. Therefore, it is a very important work to correctly select the structure and size of the sprue cup and reasonably place it on the casting.