Unformatted text preview: d transported to stones in That the most
are are anisotropic. On the other hand, particle-reinforced coma workpiece where they
dislocation responsibleﬁber-reinforced composites during service.
for theoperating cost released
matrixslip cement. deposited.
ermal ﬂuctuations. posites such as concreteare nearly isotropic in behavior. As shown in Figure 14.2–1,
concreteuniformmixture ofThefault common type ofgravel stones stacking
contains a corrosion band of variation in electrochemical
conduction band (small) sand particles and (large)the normal in a cement
m that of a result
stacking A A permissible electron
ne on which a dislocation moves bythe particles are nearly spherical and are mixed randomly, all directions
corrosion resulting from a time-varying change in the
a Burgers vector withinunit levels located above, but separated by the band
thesudden change and energy composite are equivalent. of close-packed planes. For example, in FCC
crystals the normal stacking
location valence band.
gap from, theof the weight-conscious,regions. sequencematerials with high. . ,
the surface to
The aerospace industry is local anodic and therefore requires is ABCABC .
some region of picture
speciﬁc strength and stiffness. Figure 14.2–2 shows a the crystal the stacking is and
ing with the slip direction and slip Harrier aircraft uin which composites account of the vertical takeoff
uniform and if intrinsic materials property of the
conductivity strain n in The strain in a specimen that structural
for 28% that
ABCBCABC . . . , that region is said to contain a
mation can occur. For example, in the ease withincrease maneuverability, and may provide the capabilweight,
describes before reaching the ultimate tensile strength.
d with of matter weight. Composites savestacking which electric charge is
ity to avoid
1 1 1) is a slip system and the radar throughFigure 14.2–3 shows the composite partsexternal
a material in response to an in a commercial
s the shape
state point Temperature, pressure, and composition of
Boeing 757 aircraft.
ems is represented by 〈1 1 0〉 1 1 1 .
electric ﬁeld. aspeciﬁc strength versus speciﬁc modulus for a number of comFigure 14.2–4 shows phase.
A process by which ﬁbers are conventional materials. The materials in the top right hand corner of the plot
conductor A statichigh speciﬁc stiffness and speciﬁc a high Fibrous commetal, degradation
sion in which
matrix material by passingdesirable because ofmaterial, oftenAachemical with strength.mechanism
are the ﬁber
involving the rupture of Si-O bonds due
conductivity. These materials are able to transport to discussed in
ic slurry containing theposite materials score consistently higher than conventional materials. As an interaction
Chapter 9, the elastic moduluswater at room temperature. while strength can be
id, and an organic binder.
electrical charge with is ﬁxed for a given class of metals,...
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