The production of precision castings requires pouring the solution into the cavity, and after cooling and solidifying, the shape of the required parts is initially formed. The solidification process of precision castings is an important part of precision casting.
Generally speaking, the solidification method of castings is based on different classifications. According to the properties of metal materials, it is divided into layer-by-layer solidification and paste solidification. The layer-by-layer solidification and pasty solidification are carried out according to the properties of the material, which are related to the solidification interval or crystallization interval of the metal material. The solidification region refers to the coexistence region of liquid-solid two phases in the molten metal; this so-called crystallization region is the temperature difference between the liquidus and the solidus of the molten metal. The temperature range determines how the alloy solidifies. This is the inherent property of the material. When the material is selected, its solidification method is also selected and determined. Layer-by-layer solidification is layer-by-layer solidification. That is to say, the solidification interval of the molten metal is a line. The solidification of pure metals or eutectic alloys crystallized at a constant temperature at a certain instant is layer-by-layer solidification.
According to the casting structure, it can be divided into sequential solidification and simultaneous solidification. Sequential solidification and simultaneous solidification have nothing to do with metal materials, and are mainly determined by the structure of the casting. In order to obtain a dense casting, according to the structure of the casting, find a way from the casting process to force the casting to adopt a certain solidification method. Simultaneous solidification means that the entire casting is solidified at the same time. The solidification zone of the casting is very wide, and even during a certain period of solidification, the solidification zone runs through the entire section of the casting.
The solidification process of precision castings has different process requirements for different products. Some need to rely on the material to determine the process, and some need to consider the structural characteristics of the workpiece to determine the solidification process.