Therefore, the development of the aviation industry has promoted the application of investment casting, and the continuous improvement and improvement of investment casting has also created favorable conditions for the aviation industry to further improve performance. When the investment mold is pressed, a mold with a high surface finish of the cavity is used, so the surface finish of the investment mold is also relatively high. Therefore, the surface finish of investment castings is higher than that of general castings, generally up to Ra. Another advantage of the investment casting method is that it can cast complex castings of various alloys, especially high temperature alloy castings. Manufacture of fine arts. These patterns are difficult to manufacture by ordinary casting techniques, but are cast by the lost wax method.. Because the heat-resistant alloy materials are difficult to machine and the shape of the parts is complicated, it is impossible or difficult to manufacture by other methods. The silica sol process belongs to investment casting, which is a casting process with little or no cutting. For example, the blade of the jet engine, its streamline profile and cooling cavity, can hardly be formed by mechanical processing technology. Of course, bronze gear Manufacturers due to the complicated process of investment casting, there are many factors that affect the dimensional accuracy of castings, such as mold The shrinkage of the material, the deformation of the investment mold, the linear change of the mold shell during heating and cooling, the shrinkage rate of the alloy, and the deformation of the casting during the solidification process, etc. 2. It is not only suitable for casting of various types and alloys, but also produces castings with higher dimensional accuracy and surface quality than other casting methods, and even other casting methods are difficult to cast complex, high temperature resistant and not easy to process castings. Investment casting is developed on the basis of ancient wax casting. The base of Zenghou Yi's tomb is a series of intertwined dragons, which are connected end to end, staggered up and down, forming a multi-layered moire pattern with a hollow in the middle. The production by investment casting process can not only achieve mass production, ensure the consistency of castings, but also avoid the stress concentration of residual knife lines after mechanical processing. As far back as hundreds of years BC, ancient Chinese working people created this lost wax casting technology, which was used to cast various fine patterns and characters. You can use common tools to carve out the paraffin crafts that are the same as the Zenghouyi Tomb Zun tray you want to get, and then add a pouring system, paint, dewaxing, pouring, You can get a beautiful Zunhou Yi tomb Zunhou. Can be cast by investment casting. Zhong Ding and utensils, such as Zunhou Yi's tomb in spring and autumn. It can be seen that the investment casting method can save a lot of machine tool equipment and processing hours, and save a lot of metal raw materials. The surface of the mold cavity in direct contact with the molten metal has a high surface finish.6~3. The dimensional accuracy of investment castings is high, generally up to CT4-6 (CT10~13 for sand casting, CT5~7 for die casting)., so although the dimensional accuracy of the general investment casting is high, but its Consistency still needs to be improved (consistency of castings using medium and high temperature wax materials is much improved). In addition, the mold shell is made of a high-temperature special adhesive and a refractory paint made of refractory material and hung on the investment mold. Since then, this advanced casting process has been greatly developed, and it has been widely used in manufacturing industries such as aviation, automobiles, machine tools, ships, internal combustion engines, gas turbines, telecommunications equipment, weapons, medical equipment, and knives.