Zinc alloy die-casting is a kind of pressure-casting part. It uses a pressure-casting mechanical die-casting machine equipped with a casting mold to pour the heated liquid zinc or zinc alloy into the inlet of the die-casting machine, and then die-cast by the die-casting machine. Zinc parts or zinc alloy parts that are restricted by the shape and size of the mold. Such parts are usually called zinc alloy die castings.

    The characteristics of zinc alloy die-casting products are as follows:

    1. It has high specific gravity, weight and texture, and is stronger than plastic injection molding.

    2. Good casting performance, it can die-cast precision parts with complex shapes and thin walls, and the surface of the castings is smooth.

　　3. Surface treatment can be performed: electroplating, spraying, painting.

　　4. When melting and die-casting, it does not absorb iron, does not corrode the profiling, and does not stick to the mold.

　　 5. It has good mechanical properties and abrasion resistance at room temperature.

　　6. It has a low melting point and melts at 385°C, making it easier to form than aluminum alloy die-casting.

　　 Problems that must be paid attention to in the process of zinc alloy die casting: 　　

　　1. Poor corrosion resistance. When the impurity elements of lead, cadmium, and tin in the alloy composition exceed the standard, the casting will be aging and deformed, which is manifested as volume expansion, mechanical properties, especially plasticity, significantly decreasing, and even cracking after a long time.

Lead, tin, and cadmium have very little solubility in zinc alloys, so they concentrate on the grain boundary and become the cathode. The aluminum-rich solid solution becomes the anode, and in the presence of water vapor (electrolyte), it promotes intergranular electrochemical corrosion. Die castings are aged due to intergranular corrosion.　

　　2, aging effect

The structure of zinc alloy is mainly composed of a zinc-rich solid solution containing Al and Cu and an Al-rich solid solution containing Zn, and their solubility decreases with the decrease of temperature. However, due to the extremely fast solidification rate of die castings, the solubility of the solid solution is greatly saturated when it reaches room temperature. After a certain period of time, this kind of oversaturation will gradually be relieved, and the shape and size of the casting will slightly change.　　

　　 3. Zinc alloy die castings are not suitable for use in high and low temperature (below 0°C) working environments. Zinc alloy has better mechanical properties at room temperature. However, the tensile strength at high temperature and the impact performance at low temperature are significantly reduced.