VACUUM ASSISTED DIE CASTING
HUI HWA’s vacuum assisted die casting is the latest technology that made considerable changes in the die casting industry. In conventional die casting process, the gas entrapping is almost impossible to be eliminated from the injection sleeve and mold cavity due to the fact that the molten metal, when forced into the cavity at high pressure, will result in the air to get trapped in between, which may lead to porosity and can affect the mechanical properties of the component.
Vacuum die casting is a kind of high integrity die casting process which is able to avoid many of these defects by drawing a vacuum between the injection sleeve and mold cavity. A vacuum system maintains this vacuum in the cavity until the completion of the injection process. This will result in the cavity gas to be exhausted through a vacuum valve with a vacuum pump. By maintaining the vacuum inside the mold cavity, the alloys will flow well into blind recesses in complex shaps, thereby allowing the molten metal to merge freely without forming shuts.