Lectures 7&8 - Practice problems
Quiz 7 - Practice problems
In Figure 9.38 (in Callister) is shown the pressuretemperature phase diagram for H2O. Apply the Gibbs
phase rule at points A, B, and C; that is, specify the number of degrees of freedom at eac
University rules for the exam
We will strictly follow university rules for the exam.
There will be NO make-up for the midterm exam in
(Oct. 15, Thurs., 3:55-5:55 pm in class)
Close book, close computer
Remember to bring your cal
Lecture 3 - Practice problem solution
For the HCP crystal structure, show that the ideal c/a ratio is 1.633.
Show that the atomic packing factor for BCC is 0.68.
Calculate the radius of an iridium atom, given that Ir has an FCC crystal structure,
Lectures 11&12 - Practice problems
Estimate the theoretical fracture strength of a brittle material if it is known that fracture occurs by the
propagation of an elliptically shaped surface crack of length 0.25 mm and having a tip radius of
Lecture 2 - Practice problem solution
Given that the cp of Al is given by cp=20.7+0.0124*T (J/mol/K) in the temperature range 298 to 932 K and
that cp of Al2O3 is given by cp=106.6+0.0178*T-2,850,000*T-2 (J/mol/K) in the temperature range 298 to
Lecture 4 - Practice problems
Calculate the activation energy for vacancy formation in aluminum, given that the equilibrium number
of vacancies at 500C (773 K) is 7.57 1023 m-3. The atomic weight and density (at 500C) for aluminum
are, respectively, 26
Quiz 8 -9&10
A cylindrical rod of copper (E = 110 GPa, 16 106 psi) having a yield strength of 240 MPa (35,000 psi) is
to be subjected to a load of 6660 N (1500 lb f). If the length of the rod is 380 m
Quiz 55- -Practice
(a) Compare interstitial and vacancy atomic mechanisms for diffusion.
(b) Cite two reasons why interstitial diffusion is normally more rapid than vacancy diffusion.
(c) Prove that Dvacany=Ds
Quiz 6 6- -Practice
Show that critical nucleus size is:
(a) Rewrite the expression for the total free energy change for nucleation for the case of a cubic nucleus
of edge length a (instead of a sphere o
Lecture 1 - Practice problem solution
Allowed values for the quantum numbers of electrons are as follows:
n = 1, 2, 3, . . .
l = 0, 1, 2, 3, . . . , n 1
ml = 0, 1, 2, 3, . . . , l
Relative to the subshells,
l = 0 corresponds to an s subshell
Lectures 13&14 - Practice problem solution
19.3 1. (a) Determine the room temperature heat capacities at constant pressure for the following materials:
aluminum, silver, tungsten, and 70Cu-30Zn brass. (b) How do these values compare with one another?
MSEN 601 - 600
HOMEWORK #2: Defects and elastic properties of dislocations
1. Compare and describe the difference of different type of dislocations (edge, screw and mixed)
2. What is the difference between solid solution and second phase?
3. Describe diff
MSEN 601 600
Read textbook by Rorrer, Chapter 6-9
1. Relative to electrons and electron states, what does each of the four quantum numbers
2. What are the electron configurations for Si, Ar, Ca, Cu?
3. Why does a h
Lecture 2-5: Atomic Structure and
relation between atomic bonding & material
Nucleus of an atom is composed by protons & neutrons
Atomic number Z = # of protons i
Lecture 14-15: Diffusion
Diffusion: material transport by atomic motion
(1) Interdiffusion (or impurity diffusion)
In an alloy, atoms tend to migrate from regions of higher
concentration to lower concentration.
(2) Self diffusion
Types of dislocation activities
Two type of dislocation activities
Glide or slip: A dislocation move in its glide plane
2. Climb: A dislocation move out of its glide surface
DISLOCATIONS & MATERIALS CLASSES
Metals: Disl. motion easier.
Normal strain Fractional change along axes
Shear strain - rotation
1 u y u z
yz = zy = (
1 u z u x
zx = xz = (
1 u y u x
xy = yx = (
Volume change and strain energy
Lecture 7: Defects in Solids
no perfect crystals
all have defects = lattice irregularity
Type of defects:
line defects (dislocations)
interfacial / area/planar defects
The two stages involved in the formation of particles of a new phase are nucleation and growth. The nucleation process involves the formation of normally very small particles of the new phase(s) which are stable and capable of continued growt
a) From the solubility limit curve in Figure, at 80C the maximum concentration of sugar in the syrup is about 74 wt%. It is now possible to calculate the mass of sugar
C sugar =
msugar msugar + mwater
msugar msugar + 1000
100 = 74 wt % ,
4-2. An ideal gas, with temperature independent CP=(7/2)R, at 15oC and having an
initial volume of 60 m3, is heated to constant pressure (P=0.1013 MPa) to 30oC by
transfer of heat from a reservoir at 50oC.
Calculate Sgas, Sreservoir, Suniverse?