Advanced equipment is undoubtedly an essential factor in ensuring product quality, but the role of molds in casting is also very important. Especially for aluminum alloy and aluminum alloy auto parts manufacturing enterprises, the impact of mold durability on product quality is very obvious.

For Ferrous casting, the mold is more to form the mold cavity. Generally, the mold itself does not directly contact with the liquid metal, especially for non-metallic mold castings with complex shapes. The contact with the hot liquid metal is molding materials, mainly molding sand, which makes the molding materials become the main factor affecting the quality of castings. Aluminum alloy gravity casting is different. Because of its low melting point and good casting performance, in mass production, the shape of castings is generally formed directly by the mold, such as the aluminum alloy cylinder block and cylinder head of the engine. This is not only conducive to improving labor productivity, but also more importantly, by adjusting the temperature distribution at different parts of the mold, the structure and grain size of castings can be controlled, and the quality of castings can be improved. At the same time, Avoiding the environmental pollution caused by the extensive use of styling materials and improving the working conditions of the workshop.

As the complexity of the casting shape varies, aluminum alloy gravity casting molds also vary. Even for the same part, different casting processes often result 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 mold manufacturers in China have begun to use solidification simulation to carry out casting process aided design. Through computer simulation of mold filling and solidification process, hot junction parts that are prone to Casting defect are found and overcome. This is very important and effective for improving the reliability of casting process design and effectively preventing unnecessary rework of molds during debugging.

Secondly, the mold should have good heat capacity. A thicker mold base and module that meet the requirements not only effectively guarantees the lifespan of the mold, but also plays a very important role in regulating the temperature field during the continuous working process 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, but they do not know 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, and the internal microstructure and grain size of castings can be affected, achieving the goal of effectively controlling the mechanical properties of castings. As the name suggests, air extraction is the process of artificially discharging the gas inside the mold cavity to the outside of the mold cavity to reduce the possibility of porosity defects in the casting. At the same time, the installation of exhaust plugs can also adjust the mold temperature in local small 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 a key to ensuring the size of the casting and reducing burrs and seams, but also a key to ensuring the normal operation of the casting machine. It can be said that without a good positioning device in the mold, there will be no good qualified castings. The mold must be easy to install and disassemble, because aluminum alloy>aluminum alloy gravity casting, the mold must be removed and repainted and repaired at regular intervals. If disassembly is not convenient, it will inevitably increase the labor intensity of workers, occupy more labor time, and reduce production and efficiency.

For foundries, high-quality molds mean high-quality castings, which means lower costs, higher output value, and profits.