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Structural feature Dimension (m)
atomic bonding
missing/extra atoms
crystals (ordered atoms)
second phase particles
crystal texturing
< 10-10
10-10
10-8-10-1
10-8-10-4
> 10-6
CHAPTER 1: MATERIALS SCIENCE & ENGINEERING
1. Pick Application Determine required Properties
2. Properties Identify candidate Material(s)
3. Material Identify required Processing
Processing: changes structure and overall shapeex: casting, sintering, vapor deposition, doping forming, joining, annealing.
Properties: mechanical, electrical, thermal,magnetic, optical, deteriorative.
Material: structure, composition.
The Materials Selection Process
The Materials Selection Process
The Materials Selection Process
The Materials Selection Process
The Materials Selection Process
T (°C)-200 -100 0
Cu + 3.32 at%Ni
Cu + 2.16 at%Ni
deformed Cu + 1.12 at%Ni
1
2
3
4
5
6
Resi
stiv
ity,
(1
0-8 O
hm
-m)
0
Cu + 1.12 at%Ni
“Pure” Cu
• Electrical Resistivity of Copper:
• Adding “impurity” atoms to Cu increases resistivity.• Deforming Cu increases resistivity.
ELECTRICAL
• Thermal Conductivity of Copper: --It decreases when you add zinc!
Composition (wt%Zinc)Therm
al C
onduct
ivit
y
(W/m
-K)
400
300
200
100
00 10 20 30 40
THERMAL
• Magnetic Permeability vs. Composition: --Adding 3 atomic % Si makes Fe a better recording medium!
Magnetic FieldMagneti
zati
on
Fe+3%Si
Fe
• Magnetic Storage: --Recording medium is magnetized by recording head.
MAGNETIC
• Transmittance: --Aluminum oxide may be transparent, translucent, or opaque depending on the material structure.
single crystalpolycrystal:low porosity
polycrystal:high porosity
OPTICAL
• Stress & Saltwater... --causes cracks!
• Heat treatment: slows crack speed in salt water!
“held at 160C for 1hr before testing”
increasing loadcrack
sp
eed
(m
/s)
“as-is”
10-10
10-8
Alloy 7178 tested in saturated aqueous NaCl solution at 23C
DETERIORATIVE