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Unformatted text preview: MSE 201 Practice Exam #1 Spring, 2009 Circle your section: Name (print) Yim ‘EWM Sec. 1 MNV (Yinglin
.i "93 0 g
Sec. 2 Tu/Th (Irving) 1 have neither given nor received unauthorized aid on this test. X (signature) No notes, books, or information stored in calculator memories may be used. Cheating will be
punished severely. All of your work must be written on these pages and turned in. To receive full
or partial credit on numerical problems, you must Show your calculations in step—bystep
fashion. Units must be shown when applicable and all plots must have labeled axes. Be sure that
you read and answer all parts of each question. Multiple choice questions (3 points each): Carefully circle or write only one answer.
1. Very electronegative atoms are most likely to
I a. attract extra'clectrons "3
. give up a va ence e ectron
c. form metallic bonds
d. none of the above 2. Metallic bonding is best described by which of the following statements?
a. has high optical reﬂectivity
b. shares electrons between atoms @EEEQBT‘éTﬁ‘fcﬁgWsﬁﬁmﬁatﬁg ion cores throughout the entimial?
. has high ductility ’t‘ ‘ ‘ ’ 3. Two neon atoms (2:10) interact though
a. covalent bonding C van dermmjndln '
e. y rogen ondmg (1. None of the above. 4. The notation (123) denotes
a. a direction I b. a plane With 1ntercepts x0=l , yo: I 723113—2048;
c. a my oi dlrectlons
 d. a family of sets of parallel planes 5. The face diagonal of a FCC unit cell is
a. equivalent to the lattice ﬂmeter (a0) e ual in len th to the diametmﬁtﬁmsj; L} =5“ 2 l IL ON;
C. not a close packe direction id 2 {1 Q _ (:1. none of the above 6. The hexagonal closepacked (HCP) and facecentered cubic (FCC) lattices
a. have different atomic packing factors b. have the _same gm sequences of the close—packed planes
c. both contain closepacﬁﬁlﬁﬁb‘s’“)
d. all ofthe a ove 7. Planes in a family of crystallographic planes
a. are always close packed
b. are always parallel
Cc. wafewfe'p'iesiﬁted by {hkli}
d. all of the above 8. In which crystal structure is formation of self—interstitials most favorable? F’— ( a. BCC 23
b. FCC
c. HCP d. All of the above. 9. The density of self—interstitial defects in FCC metals is
b. high
c. the same as the density of vacancies
d. slightly greater than the density of vacancies 10. An example ofan area defect is:
a. screw dislocation
b. interstitial impurity
c. substitutional impurity 11. The Burgers vector, b, of a screw dislocation is: a. parallel to the dislocation line) b. has magnltude of zero
c. perpendicular to the dislocation line
d. none of the above 12. What is the composition in atom percent of Al in an alloy containing 58 g of Ag and 75 g of
Al? (Atomic weights: AAg = 107.87 g/mol) and AA] = 26.98 g/rnol)
a. 16 at % Al . b. 44at%Al ‘
c. 56at%A1 Omir
d. 84at%Al 13. (10points) Using the appropriate boxes below: (a) Indicate the positions of the atoms for simple metals (one atom per lattice point) having the
face—centered cubic (FCC) and the body—centered cubic (BCC) structures. (b) For each structure, draw a vector indicating one direction along which there are no spaces
between atoms, and give the direction indices for that vector on the line below each box. Use
the appropriate notation for crystallographic directions. Direction indices: 14. (6 points) Enter on the line below each box the direction indices for the crystallographic
direction indicated by the vector. Use the appropriate notation for directions. 7 t . I a u “infi laoiv ; 1;" i 1 Id}
rr 52' _ ll ‘ "‘1
U a“. .l ii I s {liar Emulmb I "' it: 2“;
X=l/2, YZI, Z=l/3 15. (6 points) Enter on the line below each box the Miller indices for the shaded planes shown. Use the appropriate notation. Owe Vb 1.3.1:" {owl .mercer’r K @i ‘1
Z bargain'S
‘ K 3’— E
“'_ 3L 2‘, k. — 7. 2.
( l Clear QQU‘MS 35— 1.. ,— \ o 3) ‘Rch‘roicrls
4 Q t 16. (6 points) In each box below, draw the direction or plane corresponding to the direction or
Miller indices shown. Make sure the vector or plane isinside the box. "Track :7}; drum "‘S'I‘M
hot, NOW 0"‘J'”
+ are {A ecmln dsrew‘m
MAL“ :néex is Ms“??— t l '1.
l 3
[121] (111) (_ 3—) Rampantls
l 2
. i ‘ i 1 7:
’3; . T’lw‘e g l t ‘_ .,
‘ ELMO" :l—MWJQJPr> ‘5 jig 1 L") < l 17. (10 points) Sketch a two—dimensionnl representation of the following defects: Grain Boundﬁ " Edge Dislocatio
f‘ 66 . l8. (8 points) Plotted below is the energy of interaction versus interatomic separation between
two atoms of a ﬁctitious element A. Draw appropriate E— and r—axes that intersect at zero
energy and zero interatomic separation and clearly label the equilibrium bond length and bond energy. E A 19. (8 points) Fe is a BCC metal at room temperature with a density of 7.87 g/cm3 and atomic
mass of 55.85 amu. Using this information calculate the atomic radius. . a 433
, 2,) u own ‘ u m _— 7.181 :2. New QGMW orbit" “:0”: G“)
Cw“; A: 65.85 03“ = 1 n A 51.11
x) _1_ ‘1 Cs, N
t) ' Vt. NA 0 A “$55951 5" t ’11) A?)
a a t 1 M ; 173cm U
73 ——'." 2‘, Nb; C“a : NA 1.513.“; QQESxm %; it) 038? mm a”; ‘_ [98 1 1“) CM
1 ‘ Cd‘ﬂ "'
Q0 I Lise“ lb m‘lq AM , .. — (J
. r‘ . 431 (OWN '
tv 0‘0 ' a
H arm hm l
M/K/J 20. (10 points) The energy for forming vacancies in Fe is 2.1 eV. At what temperature is the
fraction of vacancies to total lattice sites equal to I X 10'7? 93'
. . , _—“>" QV' Nv_..t—
(Q): C“. QZVIOM 1/ = Sugzilo minim“ , 1M0
~ C12.
NJ I c KT
N
(32¢
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Q ("at ' KT ,
. ﬁ a” (A‘ICJv‘ﬁ
m _, Q/chiOw‘s _ —____._C"é" A , — ' Q.C2U‘0:1L:K(’WJ »
T' gjouio'b 94””
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git—r.
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 Spring '08
 Brenner
 Crystallography, appropriate notation, dislocation line, direction indices, close packe direction

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