Transcript Chapter 1

Materials Science & Engineering
Course Objective...
Introduce fundamental concepts in MSE
You will learn about:
• material structure
• how structure dictates properties
• how processing can change structure
This course will help you to:
• use materials properly
• realize new design opportunities with materials
Chapter 1 - a
LECTURES
Lecturer: Goknur Cambaz Buke
Time:
PLEASE BE ON TIME
Location: A 319
Activities:
• Present new material
• Announce reading and homework
• Take quizzes and midterms*
*Make-ups given only for emergencies.
*Discuss potential conflicts beforehand.
Chapter 1 - b
About me !
• Education:
– B.Sc.: METU, Materials and
Metallurgical Engineering
– M.Sc.:METU, Materials and Metallurgical
Engineering
– Ph.D.: Drexel University,
Nanotechnology institute, Materials
Science and Engineering, USA
Chapter 1 -
OFFICE HOURS
10:00-12:00 Friday
Contact me for other special arrangements!
Activities:
• Discuss homework, quizzes, exams
• Discuss lectures, book
• Pick up missed handouts
• Any materials science related discussions
Chapter 1 - e
COURSE MATERIAL
Required text:
• Materials Science and Engineering: An Introduction
W.D. Callister, Jr., 8th edition, John Wiley and Sons,
Inc. (2007). Both book and access to accompanying
web-site are needed.
Webpage: http://ece447.cankaya.edu.tr/
Chapter 1 - f
GRADING
Attendance: 10%
Homework: 10%
Quiz: 10%
Midterm: 30%
Final: 40%
Chapter 1 - g
Introduction
• What is materials science?
• Why should we know about it?
• Materials drive our society
–
–
–
–
Stone Age
Bronze Age
Iron Age
Now?
• Silicon Age?
• Polymer Age?
• Nano Age?
Chapter 1 - 7
Four Elements of Materials Science
Material trait in terms of the kind
and magnitude of response to a
specific imposed stimulus.
Arrangement of its
internal components
Chapter 1 -
Structure, Processing, & Properties
• Properties depend on structure
ex: hardness vs structure of steel
(d)
Hardness (BHN)
600
500
400
(c)
(a)
(b)
4 mm
300
200
30 mm
30 mm
100
0.01 0.1
30 mm
Data obtained from Figs. 10.30(a)
and 10.32 with 4 wt% C composition,
and from Fig. 11.14 and associated
discussion, Callister & Rethwisch 8e.
Micrographs adapted from (a) Fig.
10.19; (b) Fig. 9.30;(c) Fig. 10.33;
and (d) Fig. 10.21, Callister &
Rethwisch 8e.
1
10 100 1000
Cooling Rate (ºC/s)
• Processing can change structure
ex: structure vs cooling rate of steel
Chapter 1 - 9
Concept Map
Chapter 1 -
THE TRASHCAN I: THE CAN
• Concept Map
– Metal
– Inorganic
– Crystalline
– Synthetic
Metal
Chapter 1 -
THE TRASHCAN II: THE RUST
• Concept Map
– Non-Metal
– Inorganic
– Crystalline
– Naturally
Occurring
– Mineral
Crystalline Ceramic
Chapter 1 -
THE TRASHCAN III: THE LINER
• Concept Map
– Non-Metal
– Organic
– Amorphous
– Synthetic
– Polymer
Polymer
Chapter 1 -
Types of Materials
• Metals:
– Strong, ductile
– High thermal & electrical conductivity
– Opaque, reflective.
• Polymers/plastics: Covalent bonding  sharing of e’s
– Soft, ductile, low strength, low density
– Thermal & electrical insulators
– Optically translucent or transparent.
• Ceramics: ionic bonding (refractory) – compounds of metallic
& non-metallic elements (oxides, carbides, nitrides, sulfides)
– Brittle, glassy, elastic
– Non-conducting (insulators)
Chapter 1 - 14
ENGINEERED MATERIALS
• ALLOYS
• COMPOSITES
Chapter 1 -
SEMICONDUCTORS
Solar Cells
OLED
Technology
Chapter 1 -
BIOMATERIALS
Example – Hip Implant
• With age or certain illnesses joints deteriorate.
Particularly those with large loads (such as hip).
Adapted from Fig. 22.25, Callister 7e.
Chapter 1 - 17
Example – Hip Implant
• Requirements
– mechanical
strength (many
cycles)
– good lubricity
– biocompatibility
Adapted from Fig. 22.24, Callister 7e.
Chapter 1 - 18
Example – Hip Implant
Adapted from Fig. 22.26, Callister 7e.
Chapter 1 - 19
Hip Implant
• Key problems to overcome
– fixation agent to hold
acetabular cup
– cup lubrication material
– femoral stem – fixing agent
(“glue”)
– must avoid any debris in cup
Ball
Acetabular
Cup and Liner
Femoral
Stem
Adapted from chapter-opening photograph,
Chapter 22, Callister 7e.
Chapter 1 - 20
BIOMIMETICS
Some paints and roof tiles have
been engineered to be selfcleaning by copying the
mechanism from the lotus
LotusChapter
leaf1 surface
Nanotechnology
Definition
The art and science of building stuff that does
stuff at the nanometer scale.
R. Smalley, Rice
University
Nobel Prize Winner
Comprised of “nanostructures” or “nanomaterials”
that possess at least one dimension that measures
approximately less than 100nm AND exhibit novel
properties.
Chapter 1 -
Size
Comparisons
•The diameter of your hair is
approximately 50,000100,000 nanometers
•Your finger nail grows 1
nanometer in 1 second
•A line of ten hydrogen
atoms lined up side by side
is 1 nanometer long
Chapter 1 -
Same Story
Explore the Properties
Synthesis of
Nanostructures
New processing
techniques
• Controlled
structure, size…
• Reduce cost
Characterization
Testing
Explore/speculate
Applications
New applications!!!!!!
New Characterization and
Testing techniques
• Better resolution….
Chapter 1 -
SOME CURRENT APPLICATIONS OF
NANOTECHNOLOGY
Chapter 1 -
SOLAR CELLS
Nanotechnology enhancements provide:
Improved efficiencies: novel
nanomaterials can harness
more of the sun’s energy
 Lower costs: some novel
nanomaterials can be made
cheaper than alternatives
 Flexibility: thin film flexible
polymers can be
manipulated to generate
electricity from the sun’s
energy

Chapter 1 -
COMPUTING
Nanotechnology enhancements provide:
Faster processing speeds:
miniaturization allows more
transistors to be packed on a
computer chip
 More memory: nanosized features
on memory chips allow more
information to be stored
 Thermal management solutions
for electronics: novel carbonbased nanomaterials carry away
heat generated by sensitive
electronics

Chapter 1 -
CLOTHING
Nanotechnology enhancements provide:
Anti-odor properties: silver
nanoparticles embedded in textiles kill
odor causing bacteria
 Stain-resistance: nanofiber coatings
on textiles stop liquids from
penetrating
 Moisture control: novel nanomaterials
on fabrics absorb perspiration and
wick it away
 UV protection: titanium nanoparticles
embedded in textiles inhibit UV rays
from penetrating through fabric

Chapter 1 -
BATTERIES
Nanotechnology enhancements provide:
Higher energy storage capacity and
quicker recharge: nanoparticles or
nanotubes on electrodes provide high
surface area and allow more current to
flow
 Longer life: nanoparticles on electrodes
prevent electrolytes from degrading so
batteries can be recharged over and
over
 A safer alternative: novel nanoenhanced electrodes can be less
flammable, costly and toxic than
conventional electrodes

Chapter 1 -
SPORTING GOODS AND EQUIPMENT
Nanotechnology enhancements provide:
Increased strength of
materials: novel carbon
nanofiber or nanotube-based
nanocomposites give the
player a stronger swing
 Lighter weight materials:
nanocomposites are typically
lighter weight than their
macroscale counterparts

Chapter 1 -
CARS
Nanotechnology enhancements provide:
Increased strength of materials:
novel carbon nanofiber or
nanotube nanocomposites are
used in car bumpers, cargo
liners and as step-assists for
vans
 Lighter weight materials:
lightweight nanocomposites
mean less fuel is used to make
car go
 the
Control
of surface characteristics: nanoscale thin films can
be applied for optical control of glass, water repellency of
windshields and to repair of nicks/scratches

Chapter 1 -
FOOD AND BEVERAGE
Nanotechnology enhancements provide:
Better, more environmentally
friendly adhesives for fast
food containers
 Anti-bacterial properties:
Nano silver coatings on
kitchen tools and countertops kill bacteria/microbes


Improved barrier properties for carbonated
beverages or packaged foods: nanocomposites
slow down the flow of gas or water vapor across
the container, increasing shelf life
Chapter 1 -
THE ENVIRONMENT
Nanotechnology enhancements provide:
Improved ability to capture groundwater
contaminants: nanoparticles with high
surface area are injected into groundwater
to bond with contaminants
 Replacements for toxic materials

Chapter 1 -
SOME FUTURE APPLICATIONS OF
NANOTECHNOLOGY
Chapter 1 -
BODY ARMOR
Nanotechnology enhancements will
provide:
Stronger materials for better protection:
nanocomposites that provide unparalleled
strength and impact resistance
 Flexible materials for more form-fitting
wearability: nanoparticle-based materials
that act like “liquid armor”
 Lighter weight materials: nanomaterials
typically weigh less than their macroscale
counterparts
 Dynamic control: nanofibers that can be
flexed as necessary to provide CPR to
soldiers or stiffen to furnish additional

Chapter 1 -
DRUG DELIVERY
Nanotechnology enhancements will
provide:
New vehicles for delivery:
nanoparticles such as buckyballs
or other cage-like structures that
carry drugs through the body
 Targeted delivery: nano vehicles
that deliver drugs to specific
locations in body
 Time release: nanostructured
material that store medicine in
nanosized pockets that release
small amounts of drugs over time

Chapter 1 -
CANCER
Nanotechnology enhancements will provide:
Earlier detection: specialized
nanoparticles that target cancer
cells only – these nanoparticles
can be easily imaged to find
small tumors
 Improved treatments: infrared
light that shines on the body is
absorbed by the specialized
nanoparticles in the cancer cells
only, leading to an increased
localized temperature that
selectively kills the cancer cells
but leaves normal cells unharmed

Chapter 1 -
Cells on Patterned
VANTA Surfaces
@ Bilkent Uni.
Erman bengu’s Group
Chapter 1 -
SENSORS
Nanotechnology enhancements will provide:


Higher sensitivity: high surface
area of nanostructures that
allows for easier detection of
chemicals, biological toxins,
radiation, disease, etc.
Miniaturization: nanoscale
fabrication methods that can be
used to make smaller sensors
that can be hidden and integrated
into various objects
Chapter 1 -
NEXT GENERATION COMPUTING
Nanotechnology enhancements will provide:
 The ability to control atomic
scale phenomena: quantum or
molecular phenomena that can
be used to represent data
 Faster processing speeds
 Lighter weight and
miniaturized computers
 Increased memory
 Lower energy consumption
Chapter 1 -
NANOROBOTICS
Nanotechnology enhancements will provide:
Miniaturized fabrication of
complex nanoscale systems:
nanorobots that propel through
the body and detect/ cure
disease or clandestinely enter
enemy territory for a specific
task
 Manipulation of tools at very
small scales: nanorobots that
help doctors perform sensitive
surgeries

Chapter 1 -
Carbon Nanotube-based Gears
With Benzyne Teeth
J. Han, et. al., Nanotechnology, 8, 95, 1997
Chapter 1 -
WATER PURIFICATION
Nanotechnology enhancements will provide:
Easier contamination removal:
filters made of nanofibers that
can remove small contaminants
 Improved desalination methods:
nanoparticle or nanotube
membranes that allow only pure
water to pass through
 Lower costs
 Lower energy use

Chapter 1 -
MORE ENERGY/ENVIRONMENT
APPLICATIONS…
Nanotechnology enhancements will provide:
Improvements to solar cells
 Improvements to batteries
 Improvements to fuel cells
 Improvements to hydrogen storage
 CO2 emission reduction: nanomaterials that do a
better job removing CO2 from power plant exhaust
 Stronger, more efficient power transmission cables:
synthesized with nanomaterials

Chapter 1 -
CHAPTER 1: MATERIALS
SCIENCE & ENGINEERING
Materials are...
engineered structures...not blackboxes!
Structure...has many dimensions...
Structural feature
atomic bonding
missing/extra atoms
crystals (ordered atoms)
second phase particles
crystal texturing
Dimension (m)
< 10 -10
10-10
10 -8 -10-1
10 -8 -10-4
> 10 -6
Chapter 1 - 1
The Materials Selection Process
1. Pick Application
Determine required Properties
Properties: mechanical, electrical, thermal,
magnetic, optical, deteriorative.
2. Properties
Identify candidate Material(s)
Material: structure, composition.
3. Material
Identify required Processing
Processing: changes structure and overall shape
ex: casting, sintering, vapor deposition, doping
forming, joining, annealing.
Chapter 1 - 46
ELECTRICAL
• Electrical Resistivity of Copper:
6
Adapted from Fig. 18.8, Callister &
Rethwisch 8e. (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.)
(10-8 Ohm-m)
Resistivity, r
5
4
3
2
1
0
-200
-100
0
T (ºC)
• Adding “impurity” atoms to Cu increases resistivity.
• Deforming Cu increases resistivity.
Chapter 1 - 47
OPTICAL
• Transmittance:
-- Aluminum oxide may be transparent, translucent, or
opaque depending on the material structure.
single crystal
polycrystal:
low porosity
polycrystal:
high porosity
Adapted from Fig. 1.2,
Callister & Rethwisch 8e.
(Specimen preparation,
P.A. Lessing; photo by S.
Tanner.)
Chapter 1 - 48
DETERIORATIVE
• Stress & Saltwater...
crack speed in salt water!
crack speed (m/s)
-- causes cracks!
• Heat treatment: slows
10-8
10-10
Adapted from chapter-opening photograph,
Chapter 16, Callister & Rethwisch 3e.
(from Marine Corrosion, Causes, and
Prevention, John Wiley and Sons, Inc., 1975.)
“as-is”
“held at
160ºC for 1 hr
before testing”
Alloy 7178 tested in
saturated aqueous NaCl
solution at 23ºC
increasing load
Adapted from Fig. 11.20(b), R.W. Hertzberg, "Deformation and
Fracture Mechanics of Engineering Materials" (4th ed.), p. 505, John
Wiley and Sons, 1996. (Original source: Markus O. Speidel, Brown
Boveri Co.)
-- material:
4 mm
7150-T651 Al "alloy"
(Zn,Cu,Mg,Zr)
Adapted from Fig. 11.26,
Callister & Rethwisch 8e. (Provided courtesy of G.H.
Narayanan and A.G. Miller, Boeing Commercial Airplane
Chapter 1 - 49
Company.)
SUMMARY
Course Goals:
• Use the right material for the job.
• Understand the relation between properties,
structure, and processing.
• Recognize new design opportunities offered
by materials selection.
Chapter 1 - 50