Engr 2110 Introduction to Material Science (for Engineers)

Dr. Richard R. Lindeke, Ph.D. B Met. Eng. University of Minnesota, 1970 Master’s Studies, Met Eng. Colorado School of Mines, 1978-79 (Electro-Slag Welding of Heavy Section 2¼ Cr 1 Mo Steels) Ph.D., Ind. Eng. Penn State University, 1987 (Foundry Engineering – CG Alloy Development)

Syllabus and Website: Review the Syllabus

Attendance is your job – come to class! Final is Common Time Monday or Tuesday

Or our regularly scheduled time (Tuesday May 12 8-10 AM)

Pop Quizzes and homework/Chapter Reviews (Ch 17/18) – (20% of your grade!)

Don’t copy from others; don’t plagiarize – its just the right thing to do!!

Course Website: http://www.d.umn.edu/~rlindek1/ENGR2110/Cover_Page.htm

Materials Science and Engineering It all about the raw materials and

how they are processed That is why we call it materials

ENGINEERING Minor differences in Raw

materials or processing parameters can mean major changes in the performance of the final material or product

Looking At CG Iron Alloy Development (Processing):

Looking At CG Iron Alloy Development (Processing):

CG Structure – but with great care!

Good Structure 45KSI YS; 55KSI UTS

Poor “Too Little”

Poor “Too Much”

Looking At CG Iron Alloy Development (Structures)

Looking At CG Iron Alloy Development (Results)

Our Text:Material Science and Engineering

An Introduction by William D. Callister, Jr

Seventh Edition, John Wiley & Sons, Inc.

Materials Science and Engineering Materials Science

The discipline of investigating the relationships that exist between the structures and properties of materials.

Materials Engineering The discipline of designing or engineering the structure

of a material to produce a predetermined set of properties based on established structure-property correlation.

Four Major Components of Material Science and Engineering:

Structure of Materials Properties of Materials Processing of Materials Performance of Materials

And Remember: Materials “Drive” our Society! Ages of “Man” we survive based on the materials we control

Stone Age – naturally occurring materials Special rocks, skins, wood

Bronze Age Casting and forging

Iron Age High Temperature furnaces

Steel Age High Strength Alloys

Non-Ferrous and Polymer Age Aluminum, Titanium and Nickel (superalloys) – aerospace Silicon – Information Plastics and Composites – food preservation, housing, aerospace and

higher speeds Exotic Materials Age?

Nano-Material and bio-Materials – they are coming and then …

And Formula One – the future of automotive is …

http://www.autofieldguide.com/articles/050701.html

Doing Materials! Engineered Materials are a function of:

Raw Materials Elemental Control Processing History

Our Role in Engineering Materials then is to understand the application and specify the appropriate material to do the job as a function of:

Strength: yield and ultimate Ductility, flexibility Weight/density Working Environment Cost: Lifecycle expenses, Environmental impact** Economic and Environmental Factors often are

the most important when making the final decision!

Example of Materials Engineering Work – Hip Implant

With age or certain illnesses joints deteriorate. Particularly those with large loads (such as hip).

Adapted from Fig. 22.25, Callister 7e.

Example – Hip Implant Requirements

mechanical strength (many cycles)

good lubricity biocompatibility

Adapted from Fig. 22.24, Callister 7e.

Example – Hip Implant

Adapted from Fig. 22.24, Callister 7e.

Solution – 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 Must hold up in body

chemistry Must be strong yet

flexible

AcetabularCup and

Liner

Ball

Femoral Stem

Introduction

List the Major Types of MATERIALS That You Know: METALS CERAMICS POLYMERS COMPOSITES ADVANCED MATERIALS

Introduction, cont. Metals

Steel, Cast Iron, Aluminum, Copper, Titanium, many others

Ceramics Glass, Concrete,

Brick, Alumina, Zirconia, SiN, SiC

Polymers Plastics, Wood,

Cotton (rayon, nylon), “glue”

Composites Glass Fiber-

reinforced polymers, Carbon Fiber-reinforced polymers, Metal Matrix Composites, etc.

Thoughts about these “fundamental” 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)

The Materials Selection Process

1. Pick Application Determine required Properties

2. Properties Identify candidate Material(s)

3. Material Identify required Processing

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

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

Material: structure, composition.

But: Properties depend on Structure (strength or hardness)

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

And:

Processing can change structure! (see above structure vs Cooling

Rate)

Another Example: Rolling of Steel

At h1, L1

low UTS low YS high ductility round grains

At h2, L2

high UTS high YS low ductility elongated grains

Structure determines Properties but Processing determines Structure!

Optical Properties of Ceramic are controlled by “Grain Structure”

Grain Structure is a function of “Solidification” processing!

Electrical Properties (of Copper):

Adapted from Fig. 18.8, Callister 7e.(Fig. 18.8 adapted from: J.O. Linde,Ann Physik 5, 219 (1932); andC.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

Re

sist

ivity

,

(10-8

Ohm

-m)

0

Cu + 1.12 at%Ni

“Pure” Cu

Electrical Resistivity of Copper is affected by:

• Contaminate level

• Degree of deformation

• Operating temperature

THERMAL Properties• 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. 19.4, Callister 7e.(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.)

Composition (wt% Zinc)

The

rmal

Con

duct

ivity

(W

/m-K

)

400

300

200

100

00 10 20 30 40

100 m

MAGNETIC Properties

• Magnetic Permeability vs. Composition: --Adding 3 atomic % Si makes Fe a

better recording medium!

Adapted from C.R. Barrett, W.D. Nix, andA.S. Tetelman, The Principles ofEngineering Materials, Fig. 1-7(a), p. 9,1973. Electronically reproducedby permission of Pearson Education, Inc.,Upper Saddle River, New Jersey.

Fig. 20.23, Callister 7e.(Fig. 20.23 is from J.U. Lemke, MRS Bulletin,Vol. XV, No. 3, p. 31, 1990.)

• Magnetic Storage: --Recording medium is magnetized by recording head.

Magnetic FieldM

ag

net

iza

tion Fe+3%Si

Fe

DETERIORATIVE Properties

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

Adapted from chapter-opening photograph, Chapter 17, Callister 7e.(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 7e. (Fig. 11.26 provided courtesy of G.H.Narayanan and A.G. Miller, Boeing CommercialAirplane 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 loadcra

ck s

pe

ed

(m

/s)

“as-is”

10-10

10-8

Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC

• Using the right material for the job.one that is most economical and

“Greenest” when life usage is considered

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

• Recognizing new design opportunities offered by materials selection.

Course Goal is to make you aware of the importance of Material Selection by: