Cast iron is a group of iron-carbon alloys with a carbon content of more than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its color when fractured: white cast iron has carbide impurities that allow cracks to pass straight through, grey cast iron has graphite flakes that deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite “nodules” which stop the crack from further progressing.

• Grey cast iron
• White cast iron
• Malleable cast iron
• Ductile cast iron

One of the most significant benefits of aluminum casting is that it creates lighter parts—with more surface finishing options than other cast alloys. Moreover, cast aluminum is versatile, and corrosion resistant; it retains high dimensional stability with thin walls and can be used in almost any industry.

Casted copper alloys have high tensile and compressive strength, have good wear qualities when subjected to metal-to-metal contact, are easily machined, have good thermal and electrical conductivity, and have high corrosion resistance for maximizing product performance. It is mostly used in the fine arts area. Some of the widely used alloys are:

• Bronze: An alloy of copper and tin.
• Brass: An alloy of copper and zinc.
• Monel/ Cupronickel: An alloy of copper and nickel.