Stainless steel precision casting is difficult to machine due to heat-resistant alloy materials, and the shape of the parts is complex, so that it is impossible or difficult to manufacture by other methods. Therefore, it is necessary to find a new precision molding process. With the improvement of materials and processes, modern investment casting methods have obtained important developments on the basis of ancient processes. Therefore, the development of the aviation industry has promoted the application of investment casting, and the continuous improvement and perfection of investment casting has also created favorable conditions for the aviation industry to further improve its performance. my country began to apply investment casting to industrial production 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, gas turbines, telecommunications equipment, weapons, medical equipment, and knives, etc. Manufacturing of fine art.
The so-called investment casting process is simply to use fusible materials (such as wax or plastic) to make a fusible model (investment or model for short), apply several layers of special refractory coatings on it, and then dry and harden it. After forming an integral shell, use steam or hot water to melt the model from the shell, then put the shell in the sand box, fill with dry sand around it, and finally put the mold in the roasting furnace through high temperature Roasting (if a high-strength mold is used, the mold shell after demolding can be directly fired without modeling). After the mold or mold is fired, molten metal is poured into it to obtain a casting.
The dimensional accuracy of investment castings is relatively high, generally up to CT4-6 (sand casting is CT10~13, die casting is CT5~7).