Types of Die Casting Machine

There are two basic types of die casting machines: hot-chamber machines and cold-chamber machines. These are then rated by how much clamping force they can apply. Typical sizes range from 400 to 4,000 short tons.

Hot-chamber machines rely upon a pool of molten metal to feed the die. At the beginning of the cycle the piston of the machine is retracted, which allows the molten metal fill the "gooseneck". The gas or oil powered piston then forces this metal out of the gooseneck into the die. The advantages of this system include fast cycle times (approximately 15 cycles a minute) and the convenience of melting the metal in the casting machine. The disadvantages of this system are that high-melting point metals cannot be utilized and aluminum cannot be used because it picks up some of the iron while in the molten pool. Due to this hot-chamber machines are primarily used with zinc, tin, and lead based alloys

Cold-chamber machines are used when the casting alloy cannot be used in hot-chamber machines; these alloys include aluminum, magnesium, copper, and zinc alloys with a large composition of aluminum. This machine works by melting the material, first, in a separate furnace. Then a precise amount of molten metal is transported to the cold-chamber machine where it is fed into an unheated shot chamber (or injection cylinder). This shot is then driven into the die by a hydraulic or mechanical piston. This biggest disadvantage of this system is the slower cycle time due to the need to transfer the molten metal from the furnace to the cold-chamber machine.