Unformatted text preview: designed to exhibit speciﬁc properties in speciﬁc directions (i.e., their
intersects the stress-strain cu
gap from, theof valence electrons is less than or equal
number valence band.
ythrough the the surface to
subjecting austenite and
is reduced by compressing it between two cylindrical to 3.
anisotropy can be beneﬁcial).
yield strength for materials t
So far, metastable state intrinsic assumed that astate, butthat
at a temperature below
An A nonequilibrium composite designed and
rolls. the bulk of our discussion has tacitlymaterials property is one that
selected for its mechanical properties. This is a reasonable assumption, since the majority
transition from elastic to plas
can persist for a very
describes the ease with which time. The free is
mold is ﬁlled with
rubber A noncrystalline longelectric charge energy has a
of modern composites are designed as or amorphous ﬂuidlike term reinforcing
structural materials. Thus, the
Ohm’s law The relationsh
local is above material in lowest however, external
phase is appropriate. Other important classes the response toenergy. at for their
transportedminimum, its is not of composites,free an are
iﬁcation takes the shape
material that through abut glass transition temperatureused
interesting electrical, thermal, or magnetic properties. For these composites the terms
and resistance which has the
d dies to make long
electric ﬁeld.indices A shorthand for expressing directions
the temperature of interest, usually room temperature.
matrix and reinforcing phase may not be suitable. For example, research is now in
oxidation A gas-phase deg
roducts such as I-beams.
Only for producingcan be rubbers. These composites a likely
progress polymersAsuperconducting wires. a metal, with willhigh consist of a
conductorplanes material, often
ssisted corrosion in which
ﬂexible core to provide mechanical support, a thin concentric layer of superconducting
which a material combines w
property that describes
ing on a surface, causing
conductivity. Theseand materialsare able to transport the
materials and expresses the
urst carbon and ceramic
materialof carry the current, A formula thatinsulating surface layer. While the bulk
ease of charge as a linear sum response to an external
ofelectrical discusses composites designed for structural applications, we will investithis chapter properties carrier motion in of the constituent
composite charge efﬁciently.
rial. ﬁber containing the
gate compositesweighted It is deﬁned as to their respective carrier
oxidation (anodic) reaction
electric ﬁeld. other properties in Section 14.6.
properties designed for in proportion the average charge
reaction that results in the pr
velocity divided by the electric ﬁeld strength.
ges resulting in the desired
14.2 HISTORY AND CLASSIFICATION OF COMPOSITES
oxygen concentration cell
molecular A version of cathodic protection
sacriﬁcial anode (dipole) polarization The temporary
A composite is a combination of a reinforcing phase present in the form of particles,
resulting from oxygen concen
alignment of permanent dipoles reinforcement cell together and
ur values, three of which
involving the intentional holds the discrete in molecules in the...
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