Investment casting is based on the ancient wax mold casting. As an ancient civilization, China is one of the countries that used this technology earlier. In the hundreds of years before BC, the ancient Chinese working people created this lost wax casting technique, which was used to cast a variety of fine patterns and texts. The products of Zhong Ding and utensils, such as the tomb of Zeng Houyi at the Spring and Autumn Period. The base of Zenghouyi's tomb is a pair of intertwined dragons. They are connected end to end and are staggered up and down to form a multi-layered cloud pattern in the middle. These patterns are difficult to manufacture by ordinary casting process, but are cast by lost wax method. The process can take advantage of the fact that the paraffin has no strength and is easy to engrave. With ordinary tools, it can engrave the paraffin-like handicrafts like the Zenghouyi tomb, and then add the pouring system, paint, dewaxing and pouring. You can get the exquisite Zenghou Yi tomb.

The practical application of modern investment casting methods in industrial production was in the 1940s. At that time, the development of aviation jet engines required the manufacture of heat-resistant alloy parts such as blades, impellers, nozzles, and the like, which were complex in shape, accurate in size, and smooth in surface. Since the heat resistant alloy material is difficult to machine, the shape of the part is so complicated that it cannot be or is difficult to manufacture by other methods. Therefore, it is necessary to find a new precision molding process, so

Precision casting processing was developed on the basis of ancient casting. As an ancient civilization, China was one of the early countries to use this technology. Until centuries BC, ancient Chinese staff created this lost wax casting technique to cast a variety of beautiful patterns and clocks. Products such as utensils, such as the Qing Dynasty, have been thick and so on. The Zenghouyi Mausoleum is a group of intertwined dragons connected to each other and staggered up and down to form a hollow multi-layer cloud pattern. These patterns are difficult to manufacture with ordinary casting techniques. The lost wax casting process can be used without the intensity of paraffin. Easy to engrave the characteristics of ordinary tools, you can engrave the same paraffin material crafts as the tomb of Zenghou, then add the pouring system, paint, dewax you can get a fine Zenghouyi mausoleum board.

The practical application of modern precision casting processing methods in industrial production was in the 1940s. At that time, the development of aviation jet engines required the manufacture of heat-resistant alloy components such as blades, impellers, nozzles and other complex shapes, precise dimensions and smooth surfaces. Since the heat resistant alloy material is difficult to process and the shape of the component is complicated, other methods cannot be or are difficult to manufacture. Therefore, it is necessary to find a new precise molding process, and then learn from the lost wax casting, improve the basis of the important development of modern precision casting processing methods in the ancient process. Therefore, the development of the aviation industry has promoted the application of precision casting processing, and the precision casting processing has been continuously improved and perfected, which has also created favorable conditions for the aviation industry to further improve its performance.

China began using die castings in industrial production in the 1960s and 1960s. Since then, this advanced casting process has been widely used in aerospace, automotive, machine tools, ships, internal combustion engines, gas turbines, communications equipment, weapons, medical equipment and cutting tools. artwork.

The so-called investment casting process is simply made of a fusible material (such as wax or plastic) made of a fusible model (called an investment or a model) with a multi-layered special refractory coating that is hardened by drying. Forming the entire outer casing, then melting or releasing steam or hot water from the casing, then placing the casing in a sandbox, filling the shape of the dry sand, and finally placing the mold in a roaster for high-temperature baking (such as using a high-strength casing) Then, the outer shell of the mold cannot be directly fired. The casting or the outer shell is fired to cast the molten metal of the casting.

Casting molds have high dimensional accuracy, generally up to CT4~6 (sand casting is CT10~13, die casting is CT5~7). Of course, due to the complicated casting process, it affects the dimensional accuracy of castings, such as shrinkage of mold materials, investment mold deformation, The number of shells changes during heating and cooling, the shrinkage of the alloy and the deformation of the casting during solidification. Therefore, although the dimensional accuracy of the conventional investment casting is high, the consistency still needs to be improved (the uniformity of the casting of the medium-high temperature wax is improved a lot).

When the mold is pressed, the surface finish is high, and the surface finish of the investment mold is relatively high. In addition, the outer shell is coated with a high-temperature special adhesive and a refractory paint refractory paint, and the finished product has a high surface finish in a mold that is in direct contact with the surface of the molten metal chamber. Therefore, the surface finish of investment casting is higher than the surface finish of ordinary castings, generally reaching Ra.1.6~3.2μm.

The biggest advantage of investment casting is that die casting has high dimensional accuracy and surface finish, so it can reduce the processing work. Only in the position where the parts require higher can leave a little margin to be processed, and even some castings only retain polishing and polishing edges. It can be used without machining. It can be seen that the use of investment casting can save a lot of machine tools and processing time, and greatly save metal materials.

Another advantage of the investment casting process is the ability to cast composite castings of various alloys, particularly cast superalloy castings.