Casting IntroductionHumans have been using and forming metals for centuries. During 5,000-6,000BC, copper was used by the Sumerians and Chaldeans in Mesopotamia. Theprimary uses were arrows, spear heads and chisels. The bronze age began3500-3300 BC. From 1000 BC iron began to be introduced.Then, the metals were heated and beaten into the desired shape. Now there aremany processes used to form metals, and a lot more is known about the effect ofthe forming processes on the properties.CastingCasting is a simple process used for many applications. Molten metal is pouredinto a mould, where it solidifies to form the required shape. Casting is used where the shape is very complicated, the alloy has such low ductility that it can't be formed by any other process or where low cost is required. The mechanical properties produced are inferior to those made by other processes.Examples of products that are cast are automotive cylinder blocks, turbine blades.Forging metalForging is another process used to form metals. In forging,one piece of normally hot metal is mechanically worked byrepetitive blows or squeezing. Forged articles have verygood mechanical properties.Examples of products that are forged are automotive crankshafts, wrenches and connecting rods.RollingIn rolling, a piece of metal is passed between two rolls, resulting ina reduction in thickness of the metal, because of the compressivestress exerted by the rolls.Mechanical properties are good, but areanisotropic((of an objector substance) having a physical property which has a differentvalue when measured in different directions. An example is wood,which is stronger along the grain than across it).Examples of products produced by rolling are sheet, foil, I-beams(from grooved rolls).