Structures of Metals and Ceramics

Question 1

dense, order packing

Answer 1

crystalline structure

Question 2

non dense random packing

Answer 2

noncrystalline

Question 3

What type of materials usually have crystalline structures?

Answer 3

Metals, many ceramics, some ploymers

Question 4

structure system crystals use

Answer 4

7 structure system

Question 5

What 3 structures do metals have?

Answer 5

Body Centered Cubic (BCC), Face Centered Cubic (FCC), and Hexagonal Close-Packed (HCP)

Question 6

APF of HCP

Answer 6

0.74

Question 7

APF of FCC

Answer 7

0.74

Question 8

Stacking Sequence of FCC

Answer 8

ABCABC

Question 9

Stacking Sequence of HCP

Answer 9

ABABAB

Question 10

APF of BCC

Answer 10

0.68

Question 11

Atoms per cell of BCC

Answer 11

2 atoms/cell

Question 12

Atoms per cell of FCC

Answer 12

4 atoms/unit cell

Question 13

Atoms per cell of FCC

Answer 13

4 atoms/unit cell

Question 14

Equal types of cations and anions, several coordination numbers

Answer 14

AX-type

Question 15

only possible when there is significant covalent bonding

Answer 15

Bond Hybridization

Question 16

factors that determine ionic crystal structure

Answer 16

Relative sizes of ions and maintenance of charge neutrality

Question 17

general densities of materials

Answer 17

metals > cermanics > polymers

Question 18

Hardest material known, high thermal conductivity

Answer 18

Diamond/Tetrahedral bonding of carbon

Question 19

layered structure of carbon; parallel hexagonal arrays of carbon, good lubricant

Answer 19

graphite

Question 20

How are directions and planes described?

Answer 20

Using 3 integers (Miller Indices)

Question 21

Why is it important to know the directions and planes of crystals?

Answer 21

Material structures and properties are related to them