The development direction of aluminum alloy gravity casting molds!

Advanced equipment is undoubtedly an essential factor in ensuring product quality, but the role of molds in casting is equally important. Especially for aluminum alloy automotive parts manufacturing enterprises, the accuracy and durability of molds have a significant impact on product quality.
In the casting of black metal, the mold is mainly used to form the mold cavity. Generally, the mold itself does not directly contact the molten metal, especially for non-metallic mold castings with complex shapes. The material in contact with the hot metal liquid is the molding material, mainly the molding sand, which makes the molding material the main factor affecting the quality of the casting. However, aluminum alloy gravity casting is different. Due to its low melting point and good casting performance, the shape of the casting is generally formed directly by the mold during mass production, such as the aluminum alloy cylinder block and cylinder head of the engine. This not only helps to improve labor productivity, but more importantly, by adjusting the temperature distribution of different parts of the mold, the microstructure and grain size of the casting can be controlled, and the quality of the casting can be improved. At the same time, it avoids environmental pollution caused by the extensive use of molding materials and improves the working conditions in the workshop.
Aluminum alloy gravity casting molds vary depending on the complexity of the casting shape. Even for the same component, using different casting processes often results in different mold forms, but regardless, aluminum alloy gravity casting molds still have their commonalities.
Firstly, it is necessary to choose a suitable casting process, as the quality of the casting process directly affects the quality of the castings and the yield of the process. Some domestic mold manufacturers have started using solidification simulation for casting process auxiliary design. Through computer simulation of filling and solidification processes, they have discovered and overcome hot junction areas that are prone to casting defects. This is very important and effective in improving the reliability of casting process design and effectively preventing unnecessary rework of molds during debugging.
Secondly, the mold should have good heat capacity. Thick mold frames and modules that meet the requirements not only effectively guarantee the lifespan of the mold, but also play a crucial role in regulating the temperature field during the continuous operation of the mold. Some mold factories, in order to reduce costs and save materials, blindly reduce the effective thickness of molds to achieve the goal of reducing weight. However, they do not realize that this not only greatly reduces the service life of molds, but also makes castings prone to deformation, affecting the dimensional accuracy of castings. In severe cases, it will lead to batch scrapping of castings, causing losses to the foundry, and more seriously, damaging the reputation of the mold factory itself.
Third, the mold should have a more reliable cooling system and air extraction system. By cooling, not only can labor productivity be effectively improved, but also the temperature field of castings can be adjusted, the cooling rate of castings can be controlled, which in turn affects the internal structure and grain size of castings, and achieves the goal of effectively controlling the mechanical properties of castings. As the name suggests, degassing is the process of artificially expelling gas from the interior of the mold cavity to the outside in order to reduce the possibility of porosity defects in castings. At the same time, installing exhaust plugs can also adjust the mold temperature in small local areas, which plays an important role in preventing and overcoming aluminum alloy cracking and shrinkage.
Fourthly, there must be a mold positioning device that matches the casting machine and a convenient mold installation system. The positioning device is not only the key to ensuring the size of the casting, reducing burrs and burrs, but also the key to ensuring the normal operation of the casting machine. It can be said that without a good positioning device, there will be no good and qualified castings for the mold. The mold must be easy to install and disassemble because aluminum alloy gravity casting requires the mold to be removed and repainted and repaired at regular intervals. If disassembly is inconvenient, it will inevitably increase the labor intensity of workers, occupy more labor time, and reduce production and efficiency.