target=”_blank”>Die-casting is the process of forcing molten metal under high pressure into mold cavities. Most die-castings are made from nonferrous metals, specifically zinc, copper, and aluminum based alloys, but ferrous metal die-castings are possible. The die casting method is especially suited for applications where a large quantity of small to medium sized parts are needed with good detail, a fine surface quality and dimensional consistency.
This level of versatility has placed die-castings among the highest volume products made in the metalworking industry. In recent years, injection-molded plastic parts have replaced some die-castings because they are cheaper and lighter. Plastic parts are a practical alternative if hardness is not required and little strength is needed.
Advantages of Die-casting
- Excellent dimensional accuracy (dependent on casting material, but typically 0.1 mm for the first 2.5 cm (0.005 in. for the first inch) and 0.02 mm for each additional centimeter (0.002 in. for each additional inch).
- Smooth cast surfaces (1—2.5 μm (40—100 μin.) rms).
- Thinner walls can be cast as compared to sand and permanent mold casting (approximately 0.75 mm (0.030 in.).
- Inserts can be cast-in (such as threaded inserts, heating elements, and high strength bearing surfaces).
- Reduces or eliminates secondary machining operations.
- Rapid production rates.
- Casting tensile strength as high as 415 MPa (60 ksi).
Disadvantages of Die-casting
- Casting weight must be between 30 grams (1 oz) and 10 kg (20 lb).
- Casting must be smaller than 600 mm (24 in.).
- High initial cost.
- Limited to high-fluidity metals.
- Thickest section should be less than 13 mm (0.5 in.).
- A large production volume is needed to make this an economical alternative to other processes