One of the most common metals used in investment casting processes is aluminum. Aluminum’s high strength to low weight ratio makes it ideal for industries requiring durable parts that are also lightweight, such as aerospace, medical, and electronics. This metal also has superior corrosion resistance, exceptional electrical and thermal conductivity, a resistance to harsh environments, and a resistance to high temperatures. When aluminum is used for investment casting, the parts have a smooth finish.
Customers may pick from a wide range of aluminum alloy grades for the parts. Let’s review some of the more common grades of aluminum used in investment casting processes.
A356 aluminum alloys consist mostly of pure aluminum and silicon with the lower additions of magnesium, iron, copper, zinc, and manganese. This alloy provides high amounts of strength, good elongation, and excellent ductility. The A356 grade is considered an all-purpose aluminum because it is used throughout manufacturing industries to make simple and complex parts. It is readily made and available, which helps to lower its costs.
F357 alloys are foundry-grade metals that contain mainly aluminum, silicon, and magnesium. The alloy does not contain any beryllium, as it may be used as a substitute for other aluminum alloys that contain this metal, such as A357 grades. Properties of this alloy include high strength and heat treatability.
C355 alloys is a cast-grade aluminum that has higher levels of copper along with aluminum, silicon, iron, magnesium, manganese, zinc, and titanium. It is considered less ductile than A366 yet contains very high strength. This alloy also has good weldability and corrosion resistance.