Aluminum Die Casting

Traditional die-casting process is mainly composed of four steps, or high-pressure die-casting. These four steps include mold preparation, filling, injection and falling sand, which are also the basis of various modified die-casting processes. During the preparation process, it is necessary to spray lubricant into the mold cavity. In addition to helping to control the temperature of the mold, lubricants can also help mold release. The mold can then be closed and molten metal can be injected into the mold under high pressure, which is in the range of about 10 to about 175 MPa. When the molten metal is filled, the pressure will be maintained until the casting solidified. Then putter will launch all the castings, because there may be more than one mold cavity, so each casting process may produce multiple castings. The process of falling sand needs to separate the residue, including the mold opening, runner, gate and flash. This process is usually done by squeezing the casting through a special dressing die. Other sand removal methods include sawing and grinding. If the gate is relatively fragile, you can directly beat castings, this can save manpower. Excess die can be reused after melting. The typical yield is about 67%.

High-pressure injection results in a very fast filling of the mold, so that the molten metal fills the entire mold before any part is solidified. In this way, surface discontinuities can be avoided even in thin-walled portions that are difficult to fill. However, this can also result in air entrapment because the air is hard to escape when filling the mold quickly. This problem can be reduced by placing the vent on the parting line, but even a very delicate process leaves holes in the center of the casting. Most die-castings can be completed by secondary processing some can not be completed by casting the structure, such as drilling, polishing.