ABSTRACT
Most metallic materials are subjected to plastic deformation at one stage or another during processing, to reach nal or near to the nal shape. This is carried out by applying forces to the material through a system of tooling to reach the plastic (permanent) deformation condition, i.e., to change its shape without volume change, and without bringing it to fracture or to the molten state. Metal forming also provides better control of the mechanical properties of the product. The term bulk forming implies that the product has large thickness compared to other dimensions, and that thickness is substantially changed during forming. The material to be deformed may be heated before processing to cause large deformation or to form complicated shapes. Plastic forming processes start from a cast block, and cover a wide range of processes performed sequentially to reach a nal product, as shown in Figure 9.1.
