NAME:
________________________________
MATERIALS SELECTION
FALL SEMESTER
530.352
PROF. K.J. HEMKER
MIDTERM EXAMINATION
(Closed book  closed notes  open mind)
October 28
th
, 2002
1.
We have covered a number of different topics in class.
Briefly answer 5 out of the 6
questions
listed here.
Be sure to cross out the one that you do not want me to grade.
(5 points each; 25 points total)
i)
Describe the atomic structure of polymers like polystyrine; what is the basic
structure and how big is it?
Explain the difference between thermoset and
thermoplastic, between branched and crosslinked, and between T
glass
and T
melting
ii)
Draw and label the (121) plane.
Is there a <110>type direction [uvw] on this
plane?
If so, what is it? What is the <111>type direction on this plane?
x
y
z
530.352 Materials Selection
Midterm Exam 2002
Page 1 of 9
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document1.
cont.
(answer 5 out of 6)
iii)
You work for Ferrari and your boss would like you to design a new piston rod
such that it is both lightweight and does not buckle when loaded in compression.
You may assume that piston rod is cylindrical with a diameter of 6 mm and a
length of 25 cm and that the following relations hold:
m
=
π
r
2
l
ρ
P
buckling
=
2
E I
l
2
=
3
Er
4
4
l
2
Derive the [F][G][M] equation and give the materials index (M
1
) to minimize the
weight of the sticks.
iv)
One way to slow down dislocations and make a metal stronger is to add a second
element and make a solid solution alloy.
About how much solute is there in a
solid solution alloy?
Give the empirical relation for the solid solution
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '09
 KATZ
 Materials Science, Tensile strength, Burgers vector

Click to edit the document details