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C. Palmer Die Casting
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Die Casting: Versatile and Low-Cost

Die casting was developed in the early 1900s. Die-casting is a versatile and low-cost process for manufacturing parts having complex shapes. The applications of die cast parts include automotive, aerospace, medical, appliances, toys and many more. In die casting, the metal material is melted and then forced into steel dies. The metal cools and hardens into the desired shape.

There are two types of die casting:

Hot chamber: This process involves the use of a plunger which traps a certain volume of molten metal and forces it into the die cavity through a gooseneck and nozzle. After the metal has solidified in the die cavity, the plunger is withdrawn, the die opens and the casting is ejected. Metals having low melting points such as Zinc, copper, magnesium and lead are cast using Hot chamber die casting.

Cold chamber: In this process molten metal is poured into the injection cylinder manually by a hand ladle or by an automatic ladle. The metal is forced into the die cavity at high pressures. High melting point alloys of aluminum and copper are normally cast using cold chamber die casting.

Advantages of Die Casting

Die casting has many advantages:

• Parts with complex shapes can be produced accurately.
• Parts manufactured by die casting often do not require further machining.
• Through die casting, parts with thin walls can be manufactured easily.
• Varying textures can be manufactured.
• External threads on parts can be formed using die casting.
• Integral fastening elements such as bosses and studs can be included.
• Parts without any joints can be made eliminating other processes such as welding and fastening.
• Parts produced are heat and corrosion resistant and have better electrical properties.

Materials

Some of the materials that can be die cast include:

Aluminum: Aluminum die cast parts have high dimensional stability. They are light weight and have good mechanical properties. They also have good corrosion resistance, high thermal and electrical conductivity.

Zinc: Zinc can be easily cast and has high impact strength. Zinc die cast parts can be plated easily. Zinc is cost effective for small parts.

Magnesium: Magnesium is a light-weight alloy and can be cast easily.

Copper: Copper has high hardness and corrosion resistance. Copper die cast parts also have high dimensional stability and excellent wear resistance.

Lead and Tin: Tight dimensional tolerance can be achieved by these alloys using die casting. Be aware that some states (such as California) may have restrictions on use of lead in certain applications such as plumbing.