8/10/2019 Structures Exam Solutions (1).pdf
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A. Eutectic - a mixture of substances having a minimum melting
point
B.
C. this is because ceramics do not have much elastic deformation
*
D.
E. this is accomplished by a heat treatment procedure called
thermal tempering
F. metals usually have a crystalline structure, while polymers
are generally amorphous or semicrystalline
G. liquefied polymers do not obey Newtons laws. the relationship
between the shear stress and the strain rate is non linear.
H. isomorphs - 3 phase regions eutectic - 3 single phases
I. the grains are so fine that the water cannot move through its
pores, leaving it very slippery
J. silicon carbide, tungston carbide
K. interstitial atoms are smaller and more mobile which is why
interstitial diffusion occurs faster than vacancy and
substitutionaldiffusion
L.
M. they are very strong and stiff, yet lightweight. can be
designed not to corrode.
N. Automotive tires. Windshield glass.
O. by comparing the impact energy to the temperature we can
determine when a material transitions from dictile to brittle.
P. fillers, plasticizers, stabilizers
Q. plastic deformation is difficult in ceramics because they are
so brittle. they are likely to break instead of stretching.
R. CMC's are ceramic matrix composites. Two examples are Al2O3
and SiC
S. Is a polymer derived from two monomer species. ABS plastic,
styrene
T. to be considered a biomaterial, they must not produce toxic
substances, and must be compatible with the body tissues.
