Die Casting Process

Die casting differs from ordinary permanent-mold casting in that the molten metal is forced into the molds by pressure and held under pressure during solidification. Most die castings are made from nonferrous metals and alloys, but substantial quantities of ferrous die castings now are being produced. Because of the combination of metal molds or dies, and pressure, fine sections and excellent detail can be achieved, together with tong mold life. Special zinc-, copper-, and aluminum-base alloys suitable for die casting have been developed which have excellent properties, thereby contributing to the very extensive use of the process. Because die-casting dies usually are made from hardened tool steel, they are expensive to make. In addition, the die sections must contain knockout pins, which eject the casting.