The Shaping of Materials

Abstract

Materials have to be processed into a great variety of shapes in order to make component parts of every type. The shapes required vary enormously, both in size and complexity, ranging from micro-electronic components to large castings and forgings of, perhaps, several hundred tonnes mass (1 tonne = 1000 kg = 1 Mg). The engineer must have some awareness of the range of manufacturing processes available, and of the advantages and limitations of the various processes. The properties of the material in the finished component are also influenced to a considerable extent by the type of shaping process employed, and by the conditions existing during processing. The whole range of shaping processes can be very broadly classified into four categories:

• (a) casting, namely the pouring of liquid into prepared moulds,

• (b) manipulative processes, involving plastic deformation of the material,

• (c) powder techniques, in which a shape is produced by compacting a powder,

• (d) cutting and grinding operations.