is a metal casting process that molten metal is forced into a mold cavity under high pressure. The mold cavity is designed as using two hardened tool steel dies which have been machined into shape and work similarly to an injection mold during the process. Most die castings
are made from non-ferrous metals, specifically including zinc, copper, aluminium, magnesium, lead, pewter and tin-based alloys. Depending on the type of metal being cast, a hot- or cold-chamber machine is used.
The casting equipment and the metal dies account for large capital costs and this tends to limit the process of high-volume production. Manufacture of parts using die casting is relatively simple, only containing four main steps, which keeps the incremental cost per item low. It is especially suited for a large quantity of small- to medium-sized castings, which is why die casting produces more castings than any other casting process. Die castings are characterized by a very good surface finish (by casting standards) and dimensional consistency.
Two variants are pore-free die casting, which is used to eliminate gas porosity defects; and direct injection die casting, which is used with zinc castings
to reduce scrap and increase yield.
The die casting process
involves the use of a furnace, metal, die casting machine, and die. The metal, typically a non-ferrous alloy such as aluminum or zinc, is melted in the furnace and then injected into the dies in the die casting machine. There are two main types of die casting machines - hot chamber machines (used for alloys with low melting temperatures, such as zinc) and cold chamber machines (used for alloys with high melting temperatures, such as aluminum).