Component manufacture

Publisher Summary

This chapter discusses the key parameters influencing material performance on conversion to the component form, and to describe the main manufacturing processes involved. The majority of parts comprising the bodywork of a current mass produced motor vehicle are shaped by pressworking. The automotive industry has been using aluminum sheets for low-volume applications for many years, but there is still a lack of understanding both in the design office and on the shop floor with respect to the behavior of the material. Hemming is a subassembly process that is commonly used in the automotive industry, when very compact and stiff joints are required, and where the appearance of the edges has to meet the highest standard. The design of outer body panels is largely dictated by the stylist's creativity. Aluminum being a relatively soft material; the trimming operation can lead to a poor edge condition if the tooling is not constructed, adjusted, and maintained adequately. Prior to subassembly, the edges of a panel are flanged down 90%. This operation leads to a bending mode of deformation in material that has previously been drawn or stretched. Superplastic forming (SPF) is a manufacturing technique using air pressure and single surface tooling. The major process for the manufacture of autobody components from magnesium is die casting. The cost of producing a die-cast mould is generally less than for press tooling, making the application of cast components particularly suitable for lower volume applications.