ABSTRACT
Casting is the process in which metal is heated to make it molten and then poured into a mould. Most metallic materials pass through a molten state at some stage during the shaping process. A few metallic substances are produced in powder form. The powder is then compressed and sintered to provide the required shape. In gravity die-casting, or 'permanent-mould casting' as it is now generally called, the die is of metal and may be a multi-part design if the complexity of shape of the casting demands it. Typical applications of gravity die-casting are for the production of cylinder heads, pistons, gear and die blanks and pressure die-casting to engine and pump parts, domestic appliances and toy parts. Molten metal may be cast into the mould under gravity, but if thin sections are to be formed then it will be necessary to inject the molten metal under pressure.
