INTRODUCTION TO MATERIALS
ME/NE 180 . SPRING 1986 Name:
1.
QU1Z lt 2
Consider a solid solution of 9.t i" _}r at room
Element Group Structure Atomic Radius
Cu IB I'CC 0. 1278nm
tr'e 8 BCC 0. 1241run
a) What type of solid solution would Cu forrn?
temperature.
Valence
+1, +2
+2, +3
u) what kind of interaction would you expect between cu atoms and
"t,:.""t"".in this system? Justify your answer.
2. On the BCC unit cell below
a) Sketch and identify (magnitude and direction) the Burgers vector for
nlght Eand Screr dislocatlon whose tangent vector is parallel to the
[111] direction.
b) Sketch a favorable slip plane for the dislocation in (a) and give its
Miller indices. (Recall from your homework which fanily of planes has the
highest paking density in this structure, i.e. {111}, {110} or {100}).
3. Would you expect the surface energy of a solid to be
higher, "qn"1 or lower than the grain boundary energy?