Stainless steel precision casting, also known as investment casting, is a casting process that minimizes or eliminates cutting as much as possible during the casting process. It is a widely applicable casting method with high dimensional accuracy and excellent surface quality. At the same time, the casting process is not at ultra-high temperatures, making it more suitable for casting components in high-precision industries such as aerospace and national defense.
1. Silica sol shell technology
The silica sol shell making process is widely used in the cutting-edge internal combustion engine parts casting industry. This method uses coatings with good stability, no chemical hardening process, high temperature resistance, and better deformation resistance. However, this technology also has a certain drawback, which is that it has poor thermal properties for wax molds. It can be improved by adding surfactants, but it will increase investment to a certain extent.
2. Water glass shell technology
This method was invented very early, and China introduced this technology from the Soviet Union in the 1950s and 1960s. This method has low cost, relatively simple operation, and low requirements for raw materials. The basic characteristics of the process are the use of paraffin stearic acid low-temperature mold material, and the adhesive used in the shell making process is water glass, which is widely used in stainless steel precision casting. However, the major problem with this method compared to the silica sol shell making process is that the surface quality of the resulting castings is average and the dimensional accuracy is lower. However, due to its unique cost advantage, this technology is still used in some civilian or low precision internal combustion engines in China. Since its introduction, Chinese researchers have made significant improvements to this technology.