Materials Science and Engineering - Imperfections in the atomic arrangements
Help!
|
|
||||
|---|---|---|---|---|---|
| What are the 3 types of defects? | line, point, surface
🗑
|
||||
| Based on bond strength alone, most materials SHOULD be much ____(stronger/weaker) than they are. | stronger
🗑
|
||||
| T or F? Materials usually fail by bonds breaking. | False
🗑
|
||||
| What is the difference between impurities and dopants? | dopants are put in on purpose
🗑
|
||||
| A ___ is produced when an atom is missing. | vacancy
🗑
|
||||
| Vacancies are introduced into metals and alloys during ___ at ___ temperatures or as a consequence of radiation damage. | solidification, high
🗑
|
||||
| Concentration of vacancies ___(increases/decreases) exponentially as temperature is increased. | increases
🗑
|
||||
| The Arrhenius equation for vacancies is ___. | n_v = ne^(-Q_v/RT)
🗑
|
||||
| In n_v = ne^(-Q_v/RT), n_v = ___. | number of vacancies per cm³
🗑
|
||||
| n_v = ne^(-Q_v/RT), n = ___. | number of atoms per cm³
🗑
|
||||
| n_v = ne^(-Q_v/RT), Q = ___. | activation energy
🗑
|
||||
| n_v = ne^(-Q_v/RT), R = ___. | ideal gas constant = 1.987 (cal/mol-K) or 8.31 (joules/mol-K)
🗑
|
||||
| n_v = ne^(-Q_v/RT), T = ___. | Kelvin
🗑
|
||||
| Slip most easily occurs along a ___. | dislocation
🗑
|
||||
| Name the 3 types of dislocations. | edge, screw, mixed
🗑
|
||||
| Strength of a material depends on the force required to ___, not the bond energy. | make a dislocation move (slip)
🗑
|
||||
| An edge dislocation is ___. | an extra plane of atoms
🗑
|
||||
| The deformation direction is labeled with a ___ vector. | Burgers
🗑
|
||||
| For edge dislocations, Burgers vector is ___ to the dislocation line. | perpindicular
🗑
|
||||
| The Burgers vector is the direction of the ___ force. | shear
🗑
|
||||
| An edge dislocation is so called because when slip occurs, ___. | it creates an edge on the surface
🗑
|
||||
| A screw dislocation is a ___. | ramped step
🗑
|
||||
| For screw dislocations, Burgers vector is ___ to the dislocation line. | parallel
🗑
|
||||
| When a dislocation moves it is called ___. | slip
🗑
|
||||
| Slip is easiest along ___ in the ___ directions. | close packed planes, close packed
🗑
|
||||
| Combinations of close packed planes and close packed directions are called ___. | slip systems
🗑
|
||||
| ___ metals are fairly strong, yet still ductile. | FCC
🗑
|
||||
| ___ metals are stronger, but not very ductile. | BCC
🗑
|
||||
| ___ metals are strongest, but very brittle. | HCP
🗑
|
||||
| T or F? The more ductile a material, the less strength and vice versa. | True
🗑
|
||||
| T or F? Dislocations weaken a material. | False
🗑
|
||||
| Frank Read Source says that applying force to a material ___(increases/decreases) the number of dislocations. | increases
🗑
|
||||
| T or F? Point defects make a material weaker. | False
🗑
|
||||
| Name the types of point defects. | vacancy, interstitial, substitutional, interstitialcy
🗑
|
||||
| What are the types of interstitialcy defects? | Frenkel, Schottky
🗑
|
||||
| Frenkel defects are ___. | when ions are in the wrong spot
🗑
|
||||
| Schottky defects are ___. | vacancies of a pair of ions, one anion and one cation
🗑
|
||||
| With Schottky defects, the overall charge ___. | remains neutral
🗑
|
||||
| Which defects are in ceramics only? | Frenkel and Schottky
🗑
|
||||
| T or F? Dislocations can cross grain boundaries. | False
🗑
|
||||
| Larger grain size results in ___(increased/decreased) strength. | decreased
🗑
|
||||
| The Hall-Petch equation calculates ___ and is defined as ___. | yield strength, σ_y = σ_0 + K/√d
🗑
|
||||
| For the Hall-Petch equation σ_y = σ_0 + K/√d, σ_0 = ___. | a constant for the metal
🗑
|
||||
| For the Hall-Petch equation σ_y = σ_0 + K/√d, K = ___. | a constant for the metal
🗑
|
||||
| For the Hall-Petch equation σ_y = σ_0 + K/√d, d = ___. | average diameter of the grains
🗑
|
||||
| The equation for ASTM grain size calculation is ___. | N = 2^n-1
🗑
|
||||
| N = the number of grains per ___ at a magnification of ___. | inch, 100
🗑
|
||||
| Amorphous structures are called ___. | glass
🗑
|
||||
| Amorphous metals are also called ___. | liquid metals
🗑
|
||||
| T or F? There are no slip planes in glass. | True
🗑
|
||||
| Amorphous metals are made by ___ which makes it hard for metals to crystalize. | alloying with many different sizes of atoms
🗑
|
||||
| The brand name for liquid metal is called ___. | vitreloy
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
drjolley
Popular Engineering sets