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Chapter 1

Introduction to

Materials Science

2

Course ObjectivesIntroduce fundamental concepts in Materials

Science

Provide the interrelationships among structure,

properties & processing.

3

Learning OutcomesAt the end of this course the students should be able

to:

1.Describe the classifications, structures & applications of metals, ceramics and polymers correctly.

2.Analyse deformations behavior and strengthening mechanisms relying to its structure & properties of materials clearly.

3.Apply Fick’s Law in calculating the diffusion process and its mechanism in solids

properly.

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Learning OutcomesAt the end of this course the students should be able

to:

4.Demonstrate appropriate test methods in determining mechanical properties.

5.Apply the relation between composition, microstructure and properties of metallic materials by using apposite phase diagram and heat treatment process.

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Course Synopsis

This course comprises the fundamentals of Materials Science and its applications, atomic structure, crystal structure, solidification, imperfections and solid diffusion, mechanical and physical properties, phase diagrams and transformation, synthesis, types and applications of materials.

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Course References

1.Callister W. D., 2008, Fundamentals of Materials Science and Engineering, 3rd Edition, John Wiley & Sons.

2. Smith W. F., 2004, Foundation of Materials Science and Engineering, 4th Edition, McGraw Hill.

3. Shackleford J. F. , 2000, Introduction to Materials Science for Engineers, 5th Edition, Prentice Hall.

4. Budinski K. G. and Budinski M.G., 1999, Engineering Materials: Properties and Selection, 6th Edition, Butterworth-Heinemann UK.

5. Askeland D. R., 1994, The Science and Engineering of Materials, 3rd Edition, PWS Publication Co.

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LecturesLecturer: Wan Mohd Farid bin Wan MohamadTime: 8 – 10 a.m (Tuesday)Place: BK 3, Fasa B

Tutorial/Lab. SectionsGroup 1Lecturer: Wan Mohd FaridTime: 2 – 5 p.m (Tuesday)Place: BK 1/MSTBGroup 2Lecturer: Sushiela EdayuTime: 2 – 5 p.m (Monday)Place: MCS /MSTB

Technician (G1 & G2)Mahader bin Muhamad

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Course EvaluationsCriteria %

Course work

Test 1 Test (1½ hour) 15

Assignment

1 assignmentWill be submitted 4 weeks after tutorial 15

1 Group presentation (week 15) 5

Quiz 2 Quizzes 5

Laboratory

3 Informal Group Reports (hand written)Will be submitted 3 days after lab session

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1 Formal Individual Report (hand written)Will be submitted 1 week after lab session

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Final examination

Exam 1 Final Exam (2 ½ hours) 40

Total 100

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Course SchedulesWeek1,23,45,67

8,910,11

1213,14

151617,

18,19,20

TopicGeneral Intro; Atomic Structure & Bonding

Crystalline Structures; Polymers Defects; Diffusion

Mid-Semester BreakMechanical Properties; Strength

MechanismsFailure; Phase Diagrams

Hari Raya Aidilfitri BreakPhase Transform; Appl. of Materials

Physical PropertiesRevision & Group presentation

Study week Final exam

Chapter1,23,45,6

7,89,10

11,1213

Lectures: will highlight important portions of each chapter.

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General 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?

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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.

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Example – Hip Implant

• Requirements– mechanical

strength (many cycles)

– good lubricity– biocompatibilit

y

Adapted from Fig. 22.24, Callister 7e.

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Example – Hip Implant

Adapted from Fig. 22.26, Callister 7e.

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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 & Liner

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

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

Data obtained from Figs. 11.31(a)and 11.33 with 4 wt% C composition,and from Fig. 14.8 and associateddiscussion, Callister & Rethwisch 3e.Micrographs adapted from (a) Fig.11.19; (b) Fig. 10.34;(c) Fig. 11.34;and (d) Fig. 11.22, Callister & Rethwisch 3e.

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

Structure, Processing, & Properties

Hard

ness

(B

HN

)

Cooling Rate (ºC/s)

100

200

300

400

500

600

0.01 0.1 1 10 100 1000

(d)

30 mm(c)

4 mm

(b)

30 mm

(a)

30 mm

spheroidite

martensitic

tempered martensite

pearlite + proeutectoid ferrite

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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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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

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ELECTRICAL• Electrical Resistivity of Copper:

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

Adapted from Fig. 12.8, Callister & Rethwisch 3e. (Fig. 12.8 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)-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,

r (1

0-8 O

hm

-m)

0

Cu + 1.12 at%Ni

“Pure” Cu

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THERMAL• Space Shuttle Tiles: -- Silica fiber insulation offers low heat conduction.

• Thermal Conductivity of Copper: -- It decreases when you add zinc!

Adapted fromFig. 19.4W, Callister 6e. (Courtesy of Lockheed Aerospace Ceramics Systems, Sunnyvale, CA)(Note: "W" denotes fig. is on CD-ROM.)

Adapted from Fig. 17.4, Callister & Rethwisch 3e. (Fig. 17.4 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.)

Composition (wt% Zinc)Th

erm

al C

on

duct

ivit

y

(W/m

-K)

400

300

200

100

00 10 20 30 40

100 mm

Adapted from chapter-opening photograph, Chapter 17, Callister & Rethwisch 3e. (Courtesy of LockheedMissiles and SpaceCompany, Inc.)

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

Adapted from Fig. 1.2,Callister & Rethwisch 3e.(Specimen preparation,P.A. Lessing; photo by S. Tanner.)

single crystalpolycrystal:low porosity

polycrystal:high porosity

OPTICAL

transparent translucent opaque

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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 mm-- material: 7150-T651 Al "alloy" (Zn,Cu,Mg,Zr)

Adapted from chapter-opening photograph, Chapter 11, Callister & Rethwisch 3e. (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 loadcrack

sp

eed

(m

/s)

“as-is”

10-10

10-8

Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC

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• 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

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End of Chapter

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