1. The size of the casting cannot be too large: investment casting is most suitable for casting medium and small castings with a few shells to more than ten kilograms. In recent years, although the research and production of large-scale precision castings have made great progress, after all, there is a limit, and the size and weight can not be almost unlimited like sand casting.
2. The process is complicated: There are many investment casting procedures, the process is complicated, the production cycle is long, there are many factors affecting the quality of the bag ring castings, and the requirements for the material and process are relatively strict in production.
3. Slow cooling rate of the casting: The solidification and cooling rate of the investment casting is slow, and the crystal structure is coarse. Except for special products such as directional solidified columnar crystals and single crystal mussels, the mechanical properties of general alloy castings are lower than those of the same material. In addition, the phosphorus steel prayer pieces are also prone to surface decarburization.
It should be pointed out that any process method can best exert its advantages only under certain conditions, as is investment casting. Here, meeting the requirements on product quality and performance is of paramount importance. In addition, factors such as consumption of materials and energy, production costs, prices, service life and reliability cannot be ignored. Investment casting is the most complex of all blank forming methods, and the cost of castings is also high. However, if the product is selected properly, the part design is reasonable, and the high casting cost is compensated by reducing cutting, assembly and saving metal materials. Then investment casting has good economy. Especially for those products with complex shapes, precise, high melting point alloys that are difficult to be formed, the technical and economic advantages of investment casting are undoubtedly unmatched by other processes.