Aluminium Casting: The Process That Offers High-Quality Metal Parts.

soccer918.comDie casting is a process where molten aluminum is forced under pressure into the mold. The products produced are exceptionally accurate and require minimal finishing or machining. The process of die casting is rapid, which makes it ideal for mass production of high volume parts. The two forms of die casting are hot and cold. The difference between them is related to how the molten metal is injected into the mold. In hot die casting, the hot chamber is connected to the melting pot and uses a plunger to force the molten metal through a gooseneck into the mold. In cold die casting, the melting pot is not attached to the die casting system, and the molten melt is ladled into the cold chamber where it is forced by a plunger into the mold. Vacuum die casting uses an airtight bell housing that has a sprue opening at the bottom and a vacuum outlet at the top. The process begins by submerging the sprue below the surface of the molten aluminum. A vacuum is created in the receiver creating a pressure differential between the die cavity and the molten aluminum in the crucible. --Mark Crawford The pressure differential causes the molten aluminum to flow up the sprue into the die cavity, where the molten aluminum solidifies. The die is removed from the receiver, opened, and the part is ejected.Controlling the vacuum and the pressure differential between the die cavity and molten aluminum makes it possible to control the fill rate required by part design and gating requirements. Control of the fill rate enhances the ability to determine the soundness of the finished part. Much of the expense of aluminum permanent mold casting is the machining and shaping of the mold, which is normally made from gray iron or steel. The mold is shaped into the geometric shape of the designed part with the specifications and shape of the part divided into two halves. In the injection process, the halves of the mold are tightly sealed such that no air or contaminants are present. The mold is heated prior to the pouring of the molten aluminum, which can be ladled, poured, or injected.