Week 5

Question 1

Define crystal structure

(As a question)

Answer 1

How are the atoms, ions, or molecules arranged?

Question 2

Define unit cell

Answer 2

The smallest repeating unit that can build a crystal

Question 3

Define lattice parameter

Answer 3

Question 4

Define lattice

Answer 4

Question 5

Define crystal basis

Answer 5

Question 6

Lattice + Basis = ______ _____

Answer 6

Crystal structure

Question 7

What are the 4 Bravais lattices we focus on

Answer 7

Question 8

What does an FCC look like

Answer 8

Question 9

What does a BCC look like

Answer 9

Question 10

What does a hexagonal-close packed look like

(And acronym)

Answer 10

HCP

Question 11

What does simple cubic look like

And acronym

Answer 11

SC

Question 12

What question does atomic packing factor answer

Answer 12

Question 13

SC: not normally seen in _____ (polonium = bad idea)

Answer 13

Metals

Question 14

BCC: give 2 examples

Answer 14

Steels

High temp titanium

Question 15

FCC: give 2 examples

Answer 15

Aluminum

Copper

Question 16

HCP: give 3 examples

Answer 16

Zinc

Magnesium

Low temp titanium

Question 17

BCC: what is the coordination #

(And what does this mean)

Answer 17

CN=8

(8 atoms touching the centre atom)

Question 18

FCC: what is the coordination #

Answer 18

CN=12

Question 19

What does finding the LFP looking like in a cell

Answer 19

Red line or green line

Question 20

HCP: what is the CN

Answer 20

CN=12

Question 21

Will theoretical density or experimental density be higher for metals

Answer 21

Theoretical

(Better packing)

Question 22

What does the stacking sequence for HCP look like

Answer 22

ABAB

Question 23

What does the stacking sequence for FCC look like

Answer 23

BACBAC

Question 24

What d question do miller indices answer

Answer 24

Where are we

Question 25

Miller indices: which coordinates do we always use

Answer 25

Question 26

Point coordinates: what question do they answer

Answer 26

Where are you relative to the unit cell

Question 27

Point coordinates: values represent a _____ of the lattice parameter (Use ______ to separate values)

Answer 27

Fraction (Commas)

Question 28

Directions: how to calculate?

Answer 28

Head-tail

Question 29

Directions: use ______ brackets without _____ or ______ Multiply/divide through to get _____ Use _______ instead of negative sign

Answer 29

Square, commas, spaces Integers Bars

Question 30

5 steps for finding planes

Answer 30

Question 31

Planes: when do you use round brackets and when do you use curly

Answer 31

Question 32

Directions: when do you use square brackets and when do you use angle brackets

Answer 32

Question 33

What type of toughness does Charpy testing measure

Answer 33

Impact toughness

Question 34

How does charpy testing work

Answer 34

Striking a notched sample with a pendulum hammer (set at an impact energy) and measuring the energy absorbed before the material’s fracture