179 Applications under consideration

Skin-stiffened structures become more weight-efficient if the skin itself is a sandwich structure. This issue is discussed in some detail in Chapter 10, in which optimized skin structures are compared, and illustrated by the case studies of Sections 17.1, 17.2 and 17.4. There are many more instances in which stiffness at low weight are sought. They include loudspeaker casings, display boards, overhead racks and folding tables in aircraft and in high-speed trains.

Furniture has to be light to be moveable; 'high-tech' fashion favors a metallic appearance. Metal foams with integral skins can be handled by many of the processes familiar to the furniture maker: cutting with bandsaws, joining with wood screws and adhesives, polishing to give attractive texture and surface finish. There appears to be potential for exploiting metal foams in furniture construction.

Cores for castings

Complex foam parts can replace sand cores used in foundry practice, to produce weight-saving cavities in casting. In this case the foam part will remain in the casting, saving labor and energy costs associated with the removal of the sand. In this way completely enclosed lightweight sections can be produced in castings which lead to significant improvements in mechanical, vibration and acoustic properties compared with the original hollow part.

Aesthetic applications

Metal foams appeal to industrial designers because of their surface texture, because they are novel (carrying associations of uniqueness) and because of their combination of light weight with bulk (giving reassurance of solidity in structures which are easily moved).

Chapter 18

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