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

a

Chapter 1 -

Lecturer: Goknur Cambaz Buke

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.

b

LECTURES

PLEASE BE ON TIME

Chapter 1 -

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

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Activities:• Discuss homework, quizzes, exams• Discuss lectures, book• Pick up missed handouts

10:00-12:00 Friday

Contact me for other special arrangements!

e

OFFICE HOURS

• Any materials science related discussions

Chapter 1 -

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.

f

COURSE MATERIAL

Webpage: http://ece447.cankaya.edu.tr/

Chapter 1 - g

GRADING

Attendance: 10% Homework: 10% Quiz: 10% Midterm: 30% Final: 40%

Chapter 1 - 7

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?

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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 - 9

ex: hardness vs structure of steel • Properties depend on structure

Data obtained from Figs. 10.30(a)and 10.32 with 4 wt% C composition,and from Fig. 11.14 and associateddiscussion, 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.

ex: structure vs cooling rate of steel • Processing can change structure

Structure, Processing, & Properties

Har

dnes

s (B

HN

)

Cooling Rate (ºC/s)

100

200

300

400

500

600

0.01 0.1 1 10 100 1000

(d)

30 m(c)

4 m

(b)

30 m

(a)

30 m

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Concept Map

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THE TRASHCAN I: THE CANTHE TRASHCAN I: THE CAN

• Concept MapConcept Map– MetalMetal– InorganicInorganic– CrystallineCrystalline– SyntheticSynthetic

MetalMetal

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THE TRASHCAN II: THE RUSTTHE TRASHCAN II: THE RUST

• Concept MapConcept Map– Non-MetalNon-Metal– InorganicInorganic– CrystallineCrystalline– Naturally Naturally

OccurringOccurring– MineralMineral

Crystalline CeramicCrystalline Ceramic

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THE TRASHCAN III: THE LINERTHE TRASHCAN III: THE LINER

• Concept MapConcept Map– Non-MetalNon-Metal– OrganicOrganic– AmorphousAmorphous– SyntheticSynthetic– PolymerPolymer

PolymerPolymer

Chapter 1 - 14

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)

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ENGINEERED MATERIALS

• ALLOYS

• COMPOSITES

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SEMICONDUCTORS

OLEDTechnology

Solar Cells

Chapter 1 - 17

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.

BIOMATERIALS

Chapter 1 - 18

Example – Hip Implant

• Requirements– mechanical

strength (many cycles)

– good lubricity– biocompatibility

Adapted from Fig. 22.24, Callister 7e.

Chapter 1 - 19

Example – Hip Implant

Adapted from Fig. 22.26, Callister 7e.

Chapter 1 - 20

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

Femoral Stem

Ball

AcetabularCup and Liner

Adapted from chapter-opening photograph, Chapter 22, Callister 7e.

Chapter 1 -

BIOMIMETICS

Lotus leaf surface

Some paints and roof tiles have been engineered to be self-cleaning by copying the mechanism from the lotus

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Nanotechnology

Comprised of “nanostructures” or “nanomaterials” that possess at least one dimension that measures approximately less than 100nm AND exhibit novel properties.

The art and science of building stuff that doesstuff at the nanometer scale.

R. Smalley, Rice University

Nobel Prize Winner

Definition

Chapter 1 -

Size Comparisons

•The diameter of your hair is

approximately 50,000-

100,000 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

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Same Story

Synthesis of Nanostructures

Explore the Properties

Characterization Testing

Explore/speculate Applications

New processing techniques• Controlled structure, size…• Reduce cost

New Characterization and Testing techniques• Better resolution….

New applications!!!!!!

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SOME CURRENT APPLICATIONS OF NANOTECHNOLOGY

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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

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COMPUTINGNanotechnology 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 carbon-based nanomaterials carry away heat generated by sensitive electronics

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CLOTHINGNanotechnology 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

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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 nano-enhanced electrodes can be less flammable, costly and toxic than conventional electrodes

BATTERIES

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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

SPORTING GOODS AND EQUIPMENT

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CARSNanotechnology 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 the car go 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

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FOOD AND BEVERAGENanotechnology enhancements provide:

Better, more environmentally friendly adhesives for fast food containers

Anti-bacterial properties: Nano silver coatings on kitchen tools and counter-tops 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

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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

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SOME FUTURE APPLICATIONS OF NANOTECHNOLOGY

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BODY ARMORNanotechnology 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 protection in the face of danger

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DRUG DELIVERYNanotechnology 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

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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

CANCER

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Cells on Patterned VANTA Surfaces

@ Bilkent Uni.Erman bengu’s Group

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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

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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

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NANOROBOTICSNanotechnology 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

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With Benzyne Teeth

J. Han, et. al., Nanotechnology, 8, 95, 1997

Carbon Nanotube-based Gears

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WATER PURIFICATIONNanotechnology 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

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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

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Materials are... engineered structures...not blackboxes!

Structure...has many dimensions...

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

1

CHAPTER 1: MATERIALS SCIENCE & ENGINEERING

Chapter 1 - 46

1. Pick Application Determine required Properties

Processing: changes structure and overall shapeex: casting, sintering, vapor deposition, doping forming, joining, annealing.

Properties: mechanical, electrical, thermal,magnetic, optical, deteriorative.

Material: structure, composition.

2. Properties Identify candidate Material(s)

3. Material Identify required Processing

The Materials Selection Process

Chapter 1 - 47

ELECTRICAL• Electrical Resistivity of Copper:

• Adding “impurity” atoms to Cu increases resistivity.• Deforming Cu increases resistivity.

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.)

T (ºC)-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

Res

istiv

ity,

(10-8

Oh

m-m

)

0

Cu + 1.12 at%Ni

“Pure” Cu

Chapter 1 - 48

• Transmittance: -- Aluminum oxide may be transparent, translucent, or opaque depending on the material structure.

Adapted from Fig. 1.2,Callister & Rethwisch 8e.(Specimen preparation,P.A. Lessing; photo by S. Tanner.)

single crystalpolycrystal:low porosity

polycrystal:high porosity

OPTICAL

Chapter 1 - 49

DETERIORATIVE• Stress & Saltwater... -- causes cracks!

Adapted from chapter-opening photograph, Chapter 16, Callister & Rethwisch 3e.(from Marine Corrosion, Causes, and Prevention, John Wiley and Sons, Inc., 1975.) 4 m-- material:

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 Company.)

• Heat treatment: slows crack speed in salt water!

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.)

“held at 160ºC for 1 hr before testing”

increasing loadcrac

k sp

eed

(m

/s)

“as-is”

10-10

10-8

Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC

Chapter 1 - 50

• Use the right material for the job.

• Understand the relation between properties, structure, and processing.

• Recognize new design opportunities offered by materials selection.

Course Goals:

SUMMARY