SCHEDULE
• STRUCTURE
– Intro (Ch.1), Atomic bonding (Ch.2),
– Crystal Structure (ch.3), Defects (ch.4)
• STRUCTURE-PROPERTY
– Diffusion
Diff i ((ch.5)
h 5)
– Mechanical Property (ch.6), Strengthening
(ch 7) Failure (ch.8)
(ch.7),
(ch 8)
– Phase diagram(ch.9)
• PROECESS
– Processing metal (ch.11), ceramics (ch.13),
Polymer
y
((ch. 14/15))
• PROPERTY
– Electrical(ch.18), Thermal (ch.19), Magnetic
(
(ch.20),
) Optical
O
(ch.21)
(
)
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 - 1
Chapter
p
1 - Introduction
• What is materials science? 4 Components:
• Why should we know about it?
• Materials drive our society
– Stone Age
– Bronze
B
A
Age
– Iron Age
– Now?
性能
• Silicon Age?
• Polymer Age?
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 - 2
Fig
g 1.2 Al2O3 of Different Structures
Single Crystal
單晶
Porous多孔
Polycrystalline
多晶，低孔隙度
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 - 3
Structure,, Processing,
g, & Properties
p
• Properties depend on structure
ex: hardness vs structure of steel
(d)
Hardness (BHN)
600
500
400
(b)
(a)
4 μm
300
200
30 μm
(c)
30 μm
100
0 01 0.1
0.01
01
30 μm
Data obtained from Figs. 10.30(a)
and
d 10
10.32
32 with
ith 4 wt%
t% C composition,
iti
and from Fig. 11.14 and associated
discussion, Callister 7e.
Micrographs adapted from (a) Fig.
g 9.30;(c)
( ) Fig.
g 10.33;
10.19; ((b)) Fig.
and (d) Fig. 10.21, Callister 7e.
1
10 100 1000
Cooling Rate (ºC/s)
• Processing can change structure
ex: structure vs cooling rate of steel
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 - 4
Optical microscope, OM
Transmission electron microscope
TEM
~100x
100 M
Multiple
lti l crystal
t l grains
i
~100,000x Within single crystal grain
High resolution transmission electron microscope
HRTEM
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 ~10,000,000x
Atomic structures within crystal grain
5
1.4 Types of Materials
• Metals
M t l : metallic
t lli b
bonding
di
– Strong, ductile
– high thermal & electrical conductivity
– opaque, reflective.
• Ceramics: ionic bonding (refractory) – compounds of metallic & non
nonmetallic elements (oxides, carbides, nitrides, sulfides)
– Brittle, glassy, elastic
– non-conducting (insulators)
• Polymers/plastics: Covalent bonding Æ sharing of e’s
es
– Soft, ductile, low strength, low density
– thermal & electrical insulators
– Optically translucent or transparent.
• Composites
p
• Semiconductors, Biomaterials, Smart Materials, nanomaterials
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 - 6
1.7 Advances in Mat. Sci. & Eng.
g
Lower cost
Easier process
Better properties
New applications
High added values
Recyclable? More pollution?
“Cradle-to-grave” concept
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 -
7
The Materials Selection Process
pp
1. Pick Application
Determine required
q
Properties
p
Properties: mechanical, electrical, thermal,
magnetic, optical, deteriorative.
2. Properties
Identify candidate Material(s)
Material: structure, composition.
M t i l
3 Material
3.
Id tif required
Identify
i d Processing
P
i
Processing: changes structure and overall shape
ex: casting
casting, sintering
sintering, vapor deposition
deposition, doping
forming, joining, annealing.
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 - 8
SUMMARY
Course Goals:
• Use the right material for the job.
• Understand the relation between properties,
structure, and processing.
• Recognize new design opportunities offered
b materials
by
t i l selection.
l ti
• Materials are often replaceable!
• Materials have limits!
Copyright J.K.Chen, MMRE, NTUT 2011, John Wiley & Sons, Chapter 1 - 9