Die casting is a widely used metal casting process
Die casting is a metal casting process characterized by the use of mold cavities to apply high pressure to molten metal. Depending on the type of die casting, cold chamber or hot chamber die casting machines are required. Casting equipment and molds are expensive, so the die-casting process is typically used only for mass production of large quantities of products.
Die casting is especially suitable for making a large number of small and medium sized castings, so die casting is one of the most widely used casting processes. Compared with other casting techniques, die casting has a smoother surface and higher dimensional consistency.
Three major factors of die-casting
● Die-casting machine;
● Die-casting alloy;
● Die-casting die.
Die casting machine:
The pressure room is divided into cold chamber and hot chamber.
Cold chamber die casting machine and hot chamber die casting machine.
Die casting Alloy:
1. Aluminum alloy has good thermal conductivity, electrical conductivity and cutting performance;
2. Aluminum alloy wire shrinkage is small, so it has good filling performance;
3. Aluminum alloy has low density and high strength. Its ratio of tensile strength to density is 9 ~ 15.
4. Aluminum alloy has good corrosion resistance and oxidation resistance, most of the aluminum alloy in fresh water, sea water, concentrated nitric acid, nitric acid, gasoline and various organic compounds have good corrosion resistance.
1. Low hardness and poor wear resistance;
2. During solidification, the volume contraction is relatively large, about 6.6%;
3. Relatively high linear expansion coefficient;
4. Easy to stick mold, the iron content should be controlled in the range of 0.8% to 0.9%;
5. Low melting point and limited use of high temperature.
Aluminum alloy can replace bronze as low, medium speed, medium temperature and heavy load bearing, the price is 50% lower than that of bronze bearing.
It can also be used to manufacture bearing bush and bushing by continuous casting or centrifugal casting.
Also can be used for making molds, widely used for making bearings, various pipe joints, pulley and all kinds of impact and wear castings.
Die-casting aluminum alloy is widely used in automobile, engineering construction, electric power, electronics, computers, household appliances, high-fidelity speakers, military ships, aviation, aerospace and other military fields
At present, aluminum alloy die castings are commonly used A380, A360, A390, adc-1, adc-12 and other materials. The ADC12 is equivalent to the American ASTM standard A383, while the A380 is equivalent to the Japanese standard ADC10. In Japan, ADC12 is widely used, but in the United States, A380 is widely used, the composition of the two is also close, but the Si content difference is larger, ADC12 is 9.5~12%, and the content of A380i is 7.5~9.5%, in addition, the content of Cu is also some difference, ADC12 is 1.5~3.5%, and A380 is 2.0~4.0%, other components are basically the same.