The zinc alloy die casting is a process of organically combining and using the three die-casting elements of die-casting alloy, die-casting mold, and die-casting machine. The principle is to use high pressure to press molten metal into a precision metal mold cavity at high speed, and the molten metal is cooled and condensed under pressure to form die castings. Cold and hot chamber die casting are two basic methods of the zinc die casting process.
International Foundry Network News, in recent years, my country’s zinc alloy die-casting technology has developed rapidly, and the economic and market benefits brought by it cannot be underestimated. According to experts, zamak alloy die-casting technology has the following characteristics:
1. Relatively heavy.
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 carried out: electroplating, spraying, painting, polishing, grinding, etc.
4. When melting and die-casting, it does not absorb iron, does not corrode the pressure, and does not stick to the mold.
5. It has good mechanical properties and abrasion resistance at room temperature.
6. Low melting point, easy to die-casting.
Advantages of zinc die casting
- Metal parts with messy shapes, clear outlines, thin-walled deep cavities can be made. Because molten metal maintains high fluidity under high pressure and high speed, it is possible to obtain metal parts that are difficult to process by other processing methods.
- High material utilization. Because of the high precision of die-casting parts, they can be installed and used only after a small amount of machining, and some die-casting parts can be directly installed and used. The material utilization rate is about 60%~80%, and the blank utilization rate reaches 90%.
- High production efficiency. Because of the high-speed filling, the filling time is short, the metal industry condenses quickly, and the zinc die-casting cycle speed is fast. Among various casting processes, the die-casting method has a high yield and is suitable for mass production.
- It is convenient to use inlays. It is easy to set a positioning mechanism on the zinc die-casting mold to facilitate the insert casting of inserts and meet the local special performance requirements of the die-casting parts.
Disadvantages of zinc die casting
- Because of high-speed filling and rapid cooling, the gas in the cavity is too late to be discharged, resulting in die-casting parts often having pores and oxidized inclusions, and then reducing the quality of the zamak die-casting parts. Due to the expansion of the gas in the pores at high temperatures, the appearance of the die-casting parts will bubble, so the die-casting parts with pores cannot be heat treated.
- Die-casting machines and die-casting molds are expensive and not suitable for small batch production.
- The size of die castings is restricted. Large die-casting parts cannot be die-casted due to the constraints of the clamping force of the die-casting machine and the size of the mold.
Zinc alloy die-casting technology is widely used in the injection molding process, and its main advantage is to focus on improving the quality of castings. Anyone who understands zinc alloy die casting knows that in the casting, the runner and the remaining material are part of the casting. In the casting, they have no use-value, but these are still included in the cost of the casting. Simultaneous alloys are also recyclable. Generally, these remaining materials will be returned to the original supplier in exchange for new materials. If the die casting supplier does not carry out good treatment, it will cause air pollution and environmental hazards. There are many ways to recover zinc alloy die-casting, and zinc alloy die-casting is an alloy composed of zinc as the main element, and there are other alloying elements, such as aluminum and copper. The manufacturing process of zinc alloy die casting is usually divided into two types, one is cast zinc alloy and the other is deformed zinc alloy. Each method has different characteristics for zinc alloy casting.