University of Portland
EGR 221 - Materials Science
Exam 2 (CLOSED BOOK, CLOSED NOTES)
November 2, 2007, Dr. Ken Lulay
Name
1) {15 pts} Answer true (T) or false (F):
T F The process of recovery in a metal has little or no effect on grain size.
T F Slip systems are composted of a slip direction and slip plane – these are the
directions and planes within a crystal which have the lowest atomic linear
density and planar density, respectively.
T F Equilibrium solid phases are stable (lowest free energy) and will not change
phase even if they are heated sufficiently to cause them to completely melt.
T F Resolved shear stress is a material property.
T F Hardness and tensile strength are directly related. In other words, if you
increase the tensile strength of a material you also increase the hardness.
2) {20 pts} Fill in the blanks with the correct terminology:
a) When a material is plastically deformed it may become stronger and harder. This is
referred to as .
b) is a type of fracture for which significant plastic
deformation occurs.
c) A homogeneous portion of a system that has uniform physical and chemical
characteristics is called a:
d) The time dependent strain that can occur in materials at elevated temperatures is
referred to as .
e) The material property that characterizes a material’s ability to withstand deformation
by surface indentation or abrasion is:
3) Use the copper-nickel phase diagram below (next page) to answer the following
questions. For FULL CREDIT, make marks on the diagram to communicate what
you are doing. SHOW all of your work! Unless otherwise stated, the alloy is 60wt%
nickel (Ni) and 40wt% copper (Cu) at 1320°C
