Die Casting (Permanent Mold)

The die casting process is a name given to metal casting processes that utilize metal molds or permanent dies. There are really several distinct processes included under the general name. The die casting process actually has three main sub-processes. These are: (1) permanent mold casting, also called gravity die casting, (2) low-pressure die casting, and (3) high-pressure die casting. The three processes differ mainly in the amount of pressure that is used to force the molten metal into the die. The advantages of such a process include high production rates, exceptional dimensional repeatability, low part costs, and less machining due to reduced casting finish stock. The great heat transfer rate obtained by means of metal molds can further refine and improve the final cast structure, and therefore the mechanical properties, of the castings. The disadvantages are design limitations due to metal dies, higher initial die cost, and longer lead time for die construction and for changes to the die caused by a casting design change.