MAE 20
Fall 2015
Assignment 2
3.4 For the HCP crystal structure, show that the ideal c/a ratio is 1.633.
Solution
We are asked to show that the ideal c/a ratio for HCP is 1.633. A sketch of one-third of an HCP unit cell is
shown below.
Consider the tetrah
1
Summer, 2008
SAMPLE EXAM
MAE 20, Elements of Materials Science Mid term Exam
1. One page of notes/formula sheet allowed 2. The number of points is indicated next to the question
Question 1 Define the term: atomic packing fraction. Show that th
MAE 20 (Summer, 2008) Homework 3 - SOLUTIONS
(1) From the figure, the fatigue strength at one million cycles is 22 MPa. The maximum stress is +22MPa, the minimum stress is -22MPa, and the mean stress is 0MPa. A high frequency will cause heating of t
MAE 20 Homework 2 Due on Wednesday (July 16), at the beginning of class
Clearly show the detailed steps in your solutions.
July 9, 2008
1. Calculate the number of vacancies per cm3, expected in Copper at 1080 oC (just below the melting point). The
MAE 20: Summer, 2008 Homework 1 (Solutions)
(a) No! Springs are intended to resist high elastic forces, where only the atomic bonds are
stretched when the force is applied. Generally, ceramics would satisfy this requirement. However, we would like t
MAE 20
Fall 2016
Homework assignment #3
Due Thurs., Oct. 13 at the beginning of class
Finish reading Chapter 4, start reading Chapter 5, work problems:
3.73
The figure below shows the first five peaks of the x-ray diffraction pattern for tungsten (W),
whi
MAE 20
Fall 2015
Assignment 4
4.6 Atomic radius, crystal structure, electronegativity, and the most common valence are given in the following
table for several elements; for those that are nonmetals, only atomic radii are indicated. (USING BELOW TABLE)
El
MAE 20
Fall 2015
Assignment 1
2.14 (a) What electron subshell is being filled for the rare earth series of elements on the periodic table?
(b) What electron subshell is being filled for the actinide series?
Solution
(a) The 4f subshell is being filled for
MAE 20
Fall 2015
Assignment 7
6.4 A cylindrical specimen of a nickel alloy having an elastic modulus of 207 GPa (30 106 psi) and an original
diameter of 10.2 mm (0.40 in.) experiences only elastic deformation when a tensile load of 8900 N (2000 lbf) is
ap
MAE 20
Fall 2015
Assignment 9
7.25 The lower yield point for an iron that has an average grain diameter of 1 102 mm is 230 MPa (33,000 psi).
At a grain diameter of 6 103 mm, the yield point increases to 275 MPa (40,000 psi). At what grain diameter will
th
MAE 20
Fall 2015
Assignment 8
6.44 Using the data in Problem 6.30 and Equations 6.15, 6.16, and 6.18a, generate a true stresstrue strain plot for
stainless steel. Equation 6.18a becomes invalid past the point at which necking begins; therefore, measured
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Homework 2: Solutions
(1) Iridium (Ir) has an FCC crystal structure, an atomic weight of 192.2 g/mol, and a
density of 22.4 g/cm3. Calculate the atomic radius of an Ir atom.
Solution
We are asked to determine the radius of an iridium atom, given that I
MAE 20: Homework 2
Due Thursday, January 26, 2017
(1) Iridium (Ir) has an FCC crystal structure, an atomic weight of 192.2 g/mol, and a density
of 22.4 g/cm3. Calculate the atomic radius of an Ir atom.
(2) Niobium has an atomic radius of 0.143 nm an
MAE 20: Homework 3
Due Thursday, February 2, 2017
(1) (a) Calculate the fraction of atom sites (Nv/N) that are vacant for copper (Cu) at its
melting temperature of 1084C (1357 K). Assume an energy for vacancy formation of 0.90
eV/atom.
(b) Repeat this
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Name: SID: MAE 20, Elements of Materials Science Practice Exam
1. A calculator is allowed 2. The number of points is indicated next to the question Question 1 (6 points) What is the difference between a thermoset and a thermoplastic polymer? Give
CHAPTER 12
STRUCTURES AND PROPERTIES OF CERAMICS
PROBLEM SOLUTIONS
12.1
The two characteristics of component ions that determine the crystal structure are:
1) the
magnitude of the electrical charge on each ion; and 2) the relative sizes of the
CHAPTER 10
PHASE TRANSFORMATIONS IN METALS
PROBLEM SOLUTIONS
10.1 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
CHAPTER 9
PHASE DIAGRAMS
PROBLEM SOLUTIONS
9.1 Three variables that determine the microstructure of an alloy are 1) the alloying elements present, 2) the concentrations of these alloying elements, and 3) the heat treatment of the alloy.
9.2 In or
CHAPTER 8
FAILURE
PROBLEM SOLUTIONS
8.1 Several situations in which the possibility of failure is part of the design of a component or product are as follows: (1) the pull tab on the top of aluminum beverage cans; (2) aluminum utility/light poles
CHAPTER 7
DISLOCATIONS AND STRENGTHENING MECHANISMS
PROBLEM SOLUTIONS
7.1 The dislocation density is just the total dislocation length per unit volume of material (in this case per 3 5 -2 cubic millimeters). Thus, the total length in 1000 mm of ma
CHAPTER 6 MECHANICAL PROPERTIES OF METALS
PROBLEM SOLUTIONS
6.1
This problem asks that we derive Equations (6.4a) and (6.4b), using mechanics of materials principles. In Figure (a) below is shown a block element of material of cross-sectional area