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Introduction to Materials Science & Engineering Course Objective... Introduce fundamental concepts in Materials Science

You will learn about: • material structure • how h structure t t dictates di t t properties ti • how processing can change structure

This course will help you to: • use materials properly • realize new design opportunities with materials Chapter 1 - 1

LECTURES Lecturer: 박 광헌 (Kwangheon Park) Time: Tue,Thu. 9:00 – 10:30am Location:1 365 Location:1-365 Activities: • Present P t new material t i l • Announce reading and homework • Take quizzes and final

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COURSE MATERIALS Required text: • Fundamentals of Materials Science and Engineering, Engineering W.D. Callister, Jr. and D.G. Rethwisch, 3rd edition, John Wiley and Sons, Inc. (2008).

Optional Material: • The principles of engineering materials, Barrett, Nix, and Tetelman

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COURSE WEBSITES Course Website: http://web.kyunghee.ac.kr/~kpark/ • Syllabus • Lecture notes • Answer keys • Grades

Text Website: http://www.wiley.com/college/callister

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Chapter p 1 - Introduction • What is materials science? • Why should we know about it? • Materials drive our society – – – –

Stone Age Bronze Age Iron Age Now? • Silicon Age? g • Polymer Age?

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Structure,, Processing, g, & Properties p • Properties depend on structure ex: hardness vs structure of steel (d)

Hardness (BHN)

600 500 400

(c) (a)

(b) 4 m

300 200

30 m

30 m

100 0 01 0.1 0.01 01

30 m

Data obtained from Figs. 11.31(a) and d 11 11.33 33 with ith 4 wt% t% C composition, iti and from Fig. 14.8 and associated discussion, Callister & Rethwisch 3e. Micrographs adapted from (a) Fig. 11.19; ((b)) Fig. g 10.34;(c) ( ) Fig. g 11.34; and (d) Fig. 11.22, Callister & Rethwisch 3e.

1 10 100 1000 Cooling Rate (ºC/s)

• Processing can change structure ex: structure vs cooling rate of steel Chapter 1 - 6

Types yp 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, Brittle glassy glassy, elastic – Non-conducting (insulators)

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The Materials Selection Process pp 1. Pick Application

Determine required q Properties p

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

2. Properties

Identify candidate Material(s)

Material: structure, composition.

M t i l 3 Material 3.

Id tif required Identify i d Processing P i

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

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ELECTRICAL • Electrical Resistivity of Copper: 6

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. Th Thomson, Ph i off S Physics Solids, lid 2nd 2 d edition, McGraw-Hill Company, New York, 1970.)

(10-8 O Ohm-m)

Resisstivity, 

5 4 3 2 1 0

-200 200

-100 100

0

T ((°C) C)

• Adding “impurity” atoms to Cu increases resistivity. • Deforming Cu C increases resistivity. resisti it Chapter 1 - 9

THERMAL -- Silica fiber insulation offers low heat conduction. Adapted from chapteropening photograph, Chapter 17, Callister & R th i h 3 Rethwisch 3e. (Courtesy (C t of Lockheed Missiles and Space Company, Inc.)

100 m

• Th Thermall C Conductivity d ti it of Copper: -- It decreases when you add zinc! The ermal Conductivityy (W/m m-K)

• Space S Sh ttl Tiles: Shuttle Til

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

400 300 200 100 0

0 10 20 30 40 Composition (wt% Zinc)

Adapted from f Fig. 17.4, Callister C & 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 g g Editor), ), American Society y for Metals,, 1979, p. 315.) Chapter 1 - 10

MAGNETIC • Magnetic Storage:

vs. Composition: p -- Adding 3 atomic % Si makes Fe a better recording medium! Mag gnetization

-- Recording medium is magnetized by recording head.

• Magnetic Permeability

Fe+3%Si Fe

Magnetic Field Fig. 18.23, Callister & Rethwisch 3e. (Fig. 18.23 is from J.U. Lemke, MRS Bulletin, Vol. XV, No. 3, p. 31, 1990.)

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 Education, Inc Inc., Upper Saddle River, New Jersey. Chapter 1 - 11

OPTICAL • Transmittance: -- Aluminum oxide mayy be transparent, p , translucent,, or opaque depending on the material structure. single crystal

polycrystal: low porosity

polycrystal: high porosity

Adapted from Fig Fig. 1 1.2, 2 Callister & Rethwisch 3e. (Specimen preparation, P.A. Lessing; photo by S. Tanner.)

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DETERIORATIVE • Stress & Saltwater...

crack speed p in salt water! crrack spee ed (m/s)

-- causes cracks!

• Heat treatment: slows 10-8

10-10

Adapted p from chapter-opening p p gp photograph, g p Chapter 16, Callister & Rethwisch 3e. (from Marine Corrosion, Causes, and Prevention, John Wiley and Sons, Inc., 1975.)

“as-is” “held at 160ºC 160 C for 1 hr before testing” Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC

i increasing i lload d

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 m

7150-T651 7150 T651 Al "alloy" alloy (Zn,Cu,Mg,Zr) Adapted from chapter chapter-opening opening photograph, Chapter 11, Callister & Rethwisch 3e. (Provided courtesy of G.H. Narayanan and A.G. Miller, Chapter 1 - 13 Boeing Commercial Airplane Company.)

SUMMARY Course Goals: • Use the right material for the job. • Understand the relation between properties, structure, and processing. • Recognize new design opportunities offered b materials by t i l selection. l ti

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