Page 251 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

230 Chapter 9 Composite Materials: Structure, General Properties, and Applications

9.7 Other Composites

Composites also may consist of coatings of various types on base metals or sub-
strates (Chapter 34). Examples are
° Plating of aluminum or other metals over plastics, generally for decorative
purposes,
° Enamels, and
° Vitreous (glasslike) coatings on metal surfaces for various functional or ornamen-
tal purposes.

Composites also are made into cutting tools and dies, such as cement carbides and
cermets. Other composites are grinding wheels made of aluminum oxide, silicon
carbide, diamond, or cubic-boron-nitride abrasive particles-all held together with
various organic, inorganic, or metallic binders (Section 26.2.2). A composite of
granite particles in an epoxy matrix has high strength, good Vibration-damping
capacity (better than gray cast iron), and good frictional characteristics. It is used in
machine-tool beds for some precision grinders.

EXAMPLE 9.4 Composites in the Aircraft Industry
High fuel prices have significantly affected the In addition to the amount of composite
operations of the aerospace industry, and any de- materials used, there are a number of innovations in
sign advantages that lead to increased efficiency or the types and applications of composite materials,
reduced fuel consumption are being aggressively including the following:
pursued by aircraft manufacturers. One area where ° GLARE is a GLASS-Rliinforced aluminum con-
this effect is most dramatic is the increased com-
posite content in commercial aircraft, as shown in sisting of several layers of glass fiber-reinforced
polymer sandwiched between thin sheets of
Fig. 9.12.

60

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0 o
A350

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O 0 0 A340
76610 B777
0 O B767
0
1980 1985 1990 1995 2000 2005 2010 2015
introduction to market (year)

market). A = Airbus, B = Boeing.

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