High Pressure die casting tools or simply dies are made from hardened steel to withstand high temperature and extreme pressure. The die or mold or tool whichever name you call it, is a closed vessel into which molten metal is injected under high pressure and temperature, then rapidly cooling until the solidified part is sufficiently rigid for ejection from the die.
Due to its high melting point, aluminum die casting is done in cold chamber pressure die casting machine. Dies which are made of high quality tool steel (H13 Premium or Superior Grade tool steel is recommended ) and hardened through heat treatment, are divided into two parts - the punch and the die, or male and female. Both parts are mounted firmly in an electrically or hydraulically driven press , also called a milling machine, of great rigidity and a well balanced spindle and cutting tools.
In a working cycle the press ram, on which the punch or the male part is mounted, descends into the fixed female part. The tool steel block interposed between the sections is cut or shaped to a prescribed form of net shape or near net shape. Like the dies, the presses range in size from small to gigantic.
The dies also may have replaceable cavities, slides, cores or other sections to lower die costs and produce holes, threads and other desired shapes. The items involved in the tooling decision include the number of cavities, number of core or slide requirements, weight of the die, machining, finish requirements, polishing and plating to name just a few.
There can be different types of die casting dies, each of which serves a critical need of the customer, are determined by the following factors -
Prototypes are generally used to produce a small number of castings under production conditions for the purpose of product testing before committing to final dies for full production. There can be a range of prototyping strategies like gravity casting, use of plaster mold, machining of previous die cast parts, rapid prototyping methods such as steriolithography, etc.