Materials Science & Engineering 280
Introduction to Engineering Materials
Objective: To introduce fundamental concepts of
materials
t i l science
i
and
d engineering.
i
i
• Structure.
• Processing/synthesis.
• Properties and testing/characterization of materials.
• Processing-structure-property-performance relation
relation.
• Materials Selection and design.
Reading: Chapter 1
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© 2007,
2007, 2008
2008 Moonsub
Moonsub Shim,
Shim, University
University of
of Illinois
Illinois. All rights reserved.
©
MSE280
Overview of today’s lecture
• Brief historical overview.
• Types of materials.
• Needs for materials.
• Properties of materials.
• Materials science and engineering:
Processing-Structure-Property-Performance
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
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In the beginning…
From Farside by Gary Larson
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
An extremely brief historical overview
• Paleolithic (40,000 to 100,000 yrs ago): Stone tools and
clayy pots
p
• Mesolithic (10,000 to 40,000 yrs ago): Extensive use of
stone tools and clay, stone statues, ochre (pigment)
• Copper Age (5,000 to 10,000 yrs ago): Copper
ornaments, earthenware, metal smelting
• Bronze Age (3,000 to 5,000 yrs ago): Bronze (Cu/Sn),
glass, iron smelting
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
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historical overview continued
• Iron Age (1000 – 3000 yrs ago): Carburized Iron,
improved forging, porcelain
• Steel and concrete (100 – 1000 yrs ago)
• Polymers (beginning early 1900s)
• Silicon (60s – )
• The present: Age of bio- and nanomaterials?
Materials can define society
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
Classification of materials
Metals: Elemental metal (iron, copper etc), Steel, Alloys, Intermetallic
compounds
Ceramics: Structural Ceramics (high-temperature load bearing),
Whitewares (e.g.
(e g porcelains)
porcelains), Glass
Glass, Electrical Ceramics (capacitors
(capacitors,
Insulators, transducers, etc.), Chemically Bonded Ceramics (e.g. cement
and concrete)…
Polymers: Plastics, Adhesives, Rubber…
Semiconductors: Group IV elements (Si, Ge…), III-V (GaAs, InP…) , II-VI
(CdSe, ZnS…), IV-VI (PbS, PbSe…)…
Composites: Particulate composites, (small particles embedded in a
different material), Laminate composites (golf club shafts, tennis rackets,
Damascus sword blades), Fiber reinforced composites (e.g. fiberglass)
Biomaterials
Nanoscale materials
© 2007, 2008 Moonsub Shim, University of Illinois
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MSE280
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Performance
Materials Engineering
Designing the structure to
achieve specific properties of
materials.
Processing
Structure
• Processing
Properties
• Structure
Materials Science
• Properties
Investigating the relationship between
structure and properties of materials.
• Performance
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
Needs for materials (i.e. final performance)
• Microelectronics: ICs, packaging, photoresists...
• Infrastructure: Concrete, metal beams…
• Environmental control: biodegradable polymers,
ion exchange…
• Communication/Information: fiber optics, LEDs…
• Energy: solar cells, batteries…
• Automotive: chassis, engine parts…
• Defense: night vision, light weight/high strength
composites for aircrafts…
aircrafts
• Biotechnology: medical implants, biocompatible
polymers, biosensors…
• Sporting goods: bicycle frames, golf clubs…
and more… (no engineering without materials).
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
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Needs for “future” materials: an example
http://www.intel.com/technology/
mooreslaw/index.htm
http://www.cit.gu.edu.
au/~s55086/qucomp/
gifs/intro.moore2.gif
Pentium 4 Processor has 42,000,000
42 000 000 transistors!
DRAM half-pitch of 35 nm will be needed by 2014.
Nanoscale materials and molecular electronics?
To achieve performance needs, an understanding of
materials’ properties is necessary!
© 2007, 2008 Moonsub Shim, University of Illinois
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MSE280
Properties of materials
Stimulus
Response (e.g.)
Mechanical
Applied load
Deformation
El t i l
Electrical
El t i field
Electric
fi ld
El t i l conduction
Electrical
d ti
Magnetic
Magnetic field
Magnetization
Thermal
Heat
Heat conduction
Optical
Light
Reflection, absorption
Deterioration (Chemical)
Chemicals
Oxidation, corrosion
g p
piezoelectric materials).
)
and combinations ((e.g.
To obtain desired properties, the material must have the
appropriate structure.
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
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Structure
• Types of atoms.
• Arrangement of atoms/molecules.
– e.g. crystal structure, polymer chain length,
crosslinking…
Structure at different length scales:
• Defects and impurities.
• Grain size.
Structural feature
Dimension (m)
• Etc…
-10
atomic bonding
missing/extra atoms
crystals (ordered atoms)
second phase particles
crystal texturing
~ 10
10 -10
10 -9 -10-1
10 -8 -10-4
> 10-6
Structure will depend on processing conditions.
© 2007, 2008 Moonsub Shim, University of Illinois
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MSE280
Structure/Processing
Dependent Properties of
Materials: Examples
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
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Mechanical
Strength versus Structure of Brass
and
Changes
g in microstructure
Figs. 21 c-d and 22 Callister
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
Electrical
Resistivity of Copper
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(10 -8 Ohm-m)
Resistivity,
ρ
5
4
3
2
1
0
Cu
+ 3.
i
t%N
32 a
i
t%N
16 a
Ni
.
2
at%
2
Cu +
1
.
+1
d Cu
e
m
r
i
defo
t%N
12 a
.
1
Cu +
u
e” C
“P u r
-200
-100
0
Adapted from Fig. 18.8, Callister 6e.
(Fig. 18.8 adapted from: J.O. Linde,
Ann Physik 5, 219 (1932); and
C.A. Wert and R.M. Thomson,
Physics of Solids, 2nd edition,
McGraw-Hill Company, New York,
1970.)
T (°C)
• Adding “impurity” atoms to Cu increases resistivity.
• Deforming Cu increases resistivity.
© 2007, 2008 Moonsub Shim, University of Illinois
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MSE280
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Thermal
• Space Shuttle Tiles:
• Thermal Conductivity
of Copper:
--It decreases when
you add zinc!
--Silica fiber insulation
offers low heat conduction.
Fig. 19.0, Callister 6e.
(Courtesy of Lockheed
Missiles and Space
Company, Inc.)
Therm
mal Conductivity
(W/m-K)
400
3 00
2 00
1 00
Adapted from
Fig. 19.4W, Callister
6e. (Courtesy of
Lockheed Aerospace
Ceramics Systems,
Sunnyvale, CA)
0
0
10
20 30 40
Composition (wt%Zinc)
Adapted from Fig. 19.4, Callister 6e.
(Fig. 19.4 is adapted from Metals Handbook:
Properties and Selection: Nonferrous alloys and
Pure Metals, Vol. 2, 9th ed., H. Baker,
(Managing Editor), American Society for Metals,
1979, p. 315.)
15
100 μm
© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
Magnetic
• Magnetic Permeability
vs. Composition:
--Adding 3 atomic % Si
makes Fe a better
recording medium!
Maggnetization
• Magnetic Storage:
--Recording medium
is magnetized by
recording head
head.
Fig. 20.18, Callister 6e.
(Fig. 20.18 is from J.U. Lemke, MRS Bulletin,
Vol. XV, No. 3, p. 31, 1990.)
Fe+3%Si
Fe
Magnetic Field
Adapted from C.R. Barrett, W.D. Nix, and
A.S. Tetelman, The Principles of
Engineering Materials, Fig. 1-7(a), p. 9,
1973. Electronically reproduced
by permission of Pearson Education, Inc.,
Upper Saddle River, New Jersey.
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
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Optical
• Transmittance:
--Aluminum oxide may be transparent, translucent, or
opaque depending on the material structure.
polycrystal:
low porosity
single crystal
polycrystal:
high porosity
Adapted from Fig. 1.2,
Callister 6e.
(Specimen preparation,
P.A. Lessing; photo by J.
Telford.)
Which one is single crystal?
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
Deterioration
• Heat treatment: slows
crack speed in salt water!
crack speed (m//s)
e.g., Stress, corrosive
environments, embrittlement,
incorrect structures from improper
p p
alloying or heat treatments, …
10-8
10-10
• Stress & Saltwater...
--causes cracks!
“as-is”
“h ld att
“held
160C for 1hr
before testing”
Alloy 7178 tested in
saturated aqueous NaCl
solution at 23C
increasing load
Adapted from Fig. 11.20(b), R.W. Hertzberg, "Deformation and
Fracture Mechanics of Engineering Materials" (4th ed.)
Adapted from Fig. 17.0,
Callister 6e.
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
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Goals
• Survey structure and properties of various
materials.
• Understand the relationship between
processing, structure, properties, and
performance
• Apply the knowledge gained to choose the “right
material for the right job.”
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© 2007, 2008 Moonsub Shim, University of Illinois
MSE280
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