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