Aluminum, zinc and copper alloys are the materials predominantly used in die casting. Pure aluminum is rarely cast due to high shrinkage and susceptibility to hot cracking. Aluminum is a soft, durable, lightweight, ductile and malleable metal. It has a high dimensional stability for complex shapes and smooth and shiney surface. It has good mechanical properties, high thermal and electrical conductivity and retains strength at high temperatures. It is cast at a temperature of 650 ºC (1200 ºF). It readily forms alloy with many elements. It is usually cast with silicon at 9% and copper at about 3.5%. Silicon increases the melt fluidity, reduces machinability, while copper increases hardness and reduces the ductility. By greatly reducing the amount of copper (less than 0.6%) the chemical resistance is improved and reduces corrosion resistance.
The aluminum casting products are die castings made from aluminum materials. The aluminum castings that are created in the die casting process can vary greatly in size and weight, ranging from a couple ounces to 100 pounds. The automotive industry is the largest market for aluminum castings and cast products make more than half of the aluminum used in cars. Several automobile and vehicle components and accessories are also manufactured using aluminum casting, including pistons, cylinder heads, motorcycle crank case and engine blocks.
One common application of aluminum castings are housings or thin-walled containers, enclosures with many ribs and bosses on the interior. Metal housings for a variety of appliances and equipment are most of the time an aluminum die cast. Other examples of aluminum cast parts include propellers, gears, bushings, pumps, and valves. Aluminum castings form a vital component of aircrafts and rockets because of their high strength-to-weight ratio. Also widely used in other forms of transportation such as aircraft and marine engines.
Parts of small appliances, hand tools such as for carpentry, plumbing, and garden, water and air pumps, lawnmowers, and other machinery use thousands of different aluminum castings. However, cast products most often seen by consumers are cooking wares, kitchen utensils, home decorations and different appliances, electronics and casing for high tech gadgets, various children’s toys, match boxes and personal things such as jewelries, clothing ornaments and designs. These are the aluminum casting products that are first made available for everyday use.