Pay attention to the following points when producing and using aluminum alloy die-casting die?

1. When aluminum alloy liquid metal enters the mold cavity under high pressure and high speed, it will produce intense friction and impact on the surface of the formed parts of the mold, causing erosion and wear on the surface of the mold.

2. The molten aluminum alloy metal is inevitably brought in during the pouring process. The molten slag will have a very complex chemical effect on the surface of the formed parts. For example, the zinc in the copper alloy quickly diffuses to the surface of the production mold, which will form a brittle compound. The compound produced by the reaction of aluminum and iron will be like a wedge, thus accelerating the formation and development of cracks.

3. Thermal stress is the main reason for cracks on the surface of molded parts produced by production dies. In the process of producing each aluminum alloy die casting, the surface of the formed die casting is not only scoured by the high-speed and high-pressure metal liquid, but also absorbs the heat released by the metal in the solidification process, resulting in heat exchange.

In addition, due to the heat conduction of production die materials, the temperature of the surface layer of the formed part rises sharply, resulting in a large temperature difference with the interior, thus generating internal stress. When the metal liquid fills the cavity, the surface layer of the cavity first reaches high temperature and expands, while the temperature of the inner layer is low, and the relative expansion amount is small, resulting in compressive stress on the surface layer.

After the mold is opened, the cavity surface contacts with the air and is cooled by compressed air and paint to produce tensile stress. This alternating stress increases with the production. When the fatigue limit of the mold material is exceeded, plastic deformation will occur on the surface layer and cracks will occur at the grain boundary.