Page 239 - Manufacturing Engineering and Technology - Kalpakjian, Serope : Schmid, Steven R.

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2 l 8 Chapter 9 Composite Materials: Structure, General Properties, and Applications

A; tv" A »,,,¢i
f~< Laminate
§1.z%xi|
T ra
se fibers
,_____,,, "
». Continuous
Wm
Particles =-‘
(al rttittw at 2 ? Foam

ps *a 2 Q 5 y at tan.

Short or long Honeycomb
fibers, or flakes
(bl
(Cl)

FIGURE 9.2 Schematic illustration of methods of reinforcing plastics (matrix) with
(a) particles, (b) short or long fibers or flakes, and (c) continuous fibers. The laminate
structures shown in (d) can be produced from layers of continuous fibers or sandwich
structures using a foam or honeycomb core (see also Fig. 16.50).

TABLE 9.I
Types and General Characteristics of Composite Materials

Material Characteristics
Fibers
Glass High strength, low stiffness, high density; lowest cost; E (calcium
aluminoborosilicate) and S (magnesia aluminosilicate) types
commonly used
Carbon Available as high modulus or high strength; low cost; less dense
than glass; sometimes used in combination with carbon
nanotubes (see Section 8.62)
Boron High strength and stiffness; highest density; highest cost; has
tungsten filament at its center
Aramids (Kevlar) Highest strength-to-weight ratio of all fibers; high cost
Other fibers Nylon, silicon carbide, silicon nitride, aluminum oxide, boron
carbide, boron nitride, tantalum carbide, steel, tungsten,
molybdenum
Matrix materials
Thermosets Epoxy and polyester, with the former most commonly used;
others are phenolics, fluorocarbons, polyethersulfone, silicon,
and polyimides
Thermoplastics Polyetheretherketone; tougher than thermosets, but lower
resistance to temperature
Metals Aluminum, aluminum-lithium, magnesium, and titanium; fibers
are carbon, aluminum oxide, silicon carbide, and boron
Ceramics Silicon carbide, silicon nitride, aluminum oxide, and mullite;
fibers are various ceramics