Die Casting Process

The principle of the die casting process is to use high pressure to press the metal liquid into a precision metal mold cavity at high speed, and the metal liquid is cooled and solidified under pressure to form a casting. Cold and hot chamber die castings are two basic ways of die casting process. In the cold chamber die casting, the metal liquid is poured into the pressure chamber by a manual or automatic pouring device, and then the injection punch is advanced to hydraulically press the metal into the cavity. In the hot-chamber die casting process, the pressure chamber is perpendicular to the crucible, and the metal liquid automatically flows into the pressure chamber through the feeding port on the pressure chamber. The injection punch moves downwards, pushing the molten metal through the gooseneck into the cavity. After the molten metal solidifies, the die-casting mold is opened, and the casting is taken out to complete a die-casting cycle.

• Product quality is good. The castings have high dimensional accuracy, which is generally equivalent to 6 ~ 7, or even up to 4; the surface finish is good, generally equivalent to 5 ~ 8; the strength and hardness are higher, and the strength is generally 25 ~ 30% higher than that of sand casting, but the extension The rate is reduced by about 70%; the size is stable and the interchangeability is good; it can die-cast thin-walled complex castings;
• and the production efficiency is high. The machine can do die-cast 3,000 to 7000 times every eight hours on average.
• The life of the die-casting mold is long. One pair of die-casting molds and die-casting bell alloys have a service life of hundreds of thousands of times, even millions of times.
• It is easy to realize mechanization and automation.
• Excellent economic results. Due to the precise dimensions of the die-casting parts, the surface is smooth and smooth. Generally no longer use mechanical processing and use directly, or the processing volume is small, so it not only improves the metal utilization rate, but also reduces a large number of processing equipment and man-hours;
• the price of castings is easy;
• combined die casting can be used for other metal or non-metal materials. Save both assembly man-hours and metal.

• During die casting, due to the high speed of the liquid metal filling cavity and the unstable flow state, the general die casting method is easy to produce pores and cannot be heat treated.
• For intricate concave castings, die casting is more difficult;
• high melting point alloys (such as copper, black Metal), the life of the die-casting mold is low;
• it is not suitable for small batch production, mainly due to the high cost of die-casting mold manufacturing, high production efficiency of the die-casting machine, and small batch production is not economical.