What is a directional solidification?
"directional solidification" is the term casting of metal. It refers to the controlled feeding process of molten metal into a temperature -controlled mold to form part without hollow stains called shrink defects. Directional solidification is also used to improve metal during the casting process, because the impurities found in the molten metal will continue to rise to the surface of the pool, along the path of the least resistance as they are pushed up from the solid materials down. When the metal at the bottom of the mold cools down, this line of solidification moves upwards towards the molten metal feed. By regulating the flow rate for feeding the molten metal and the introduction of thermal changes in the form, stunning defects can be eliminated, because the liquid metal will naturally come across these dips and Vacaoblasti NT. Although these processes share some similar features, in progressive solidification, the cooling and stiffness process on the casting walls begins and works in. With the direction of stiffness, the solidification process begins at the bottom of the casting and travels to the top.
parallel solidification when casting is the basic cause of defects. Because the molten metal in some areas cools too quickly or remains heated in other areas for too long, it creates defects due to solidification, thermal expansion and contraction. For example, if the molten metal poured into a L -shaped mold, the metal on the corner of the mold could cool too quickly, causing a narrow profile and capturing the air pocket into the lower legs. This air pocket creates a hollow space in the finished metal part, weakening the overall structure.
Several techniques are used to check parallel solidification and stimulate directional solidification in the casting process. Thermal variations are introduced into a mold using risers or chills to control hot or cold places that could cause problems with a occupied part. Insulated sleeves are also used to ensure stable and controlled temperature for mold. Finally, the rate of flow and the temperature of the molten metal feed is carefully checked to ensure directional solidification.