Transcript Engr 2110 Introduction to Material Science (for Engineers)

Engr 2110 Introduction to
Material Science (for Engineers)
Dr. Richard R. Lindeke, Ph.D.
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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:
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Review the Syllabus
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Attendance is your job – come to class!
Final is Common Time Monday or Tuesday
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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
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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
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Materials Science
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Materials Engineering
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The discipline of investigating the relationships that exist
between the structures and properties of materials.
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:
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Structure of Materials
Properties of Materials
Processing of Materials
Performance of Materials
And Remember: Materials
“Drive” our Society!
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Ages of “Man” we survive based on the materials we control
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Stone Age – naturally occurring materials
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Bronze Age
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High Strength Alloys
Non-Ferrous and Polymer Age
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High Temperature furnaces
Steel Age
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Casting and forging
Iron Age
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Special rocks, skins, wood
Aluminum, Titanium and Nickel (superalloys) – aerospace
Silicon – Information
Plastics and Composites – food preservation, housing, aerospace and higher
speeds
Exotic Materials Age?
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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!
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Engineered Materials are a function of:
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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:
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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
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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
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Requirements
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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
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Key Problems to
overcome:
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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
Acetabular
Cup and
Liner
Ball
Femoral
Stem
Introduction
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List the Major Types of MATERIALS
That You Know:
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METALS
CERAMICS
POLYMERS
COMPOSITES
ADVANCED MATERIALS
Introduction, cont.
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Metals
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Steel, Cast Iron,
Aluminum, Copper,
Titanium, many
others
Ceramics
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Glass, Concrete,
Brick, Alumina,
Zirconia, SiN, SiC
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Polymers
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Plastics, Wood,
Cotton (rayon,
nylon), “glue”
Composites
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Glass Fiberreinforced polymers,
Carbon Fiberreinforced polymers,
Metal Matrix
Composites, etc.
Thoughts about these
“fundamental” Materials
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Metals:
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Polymers/plastics: Covalent bonding  sharing of e’s
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Strong, ductile
high thermal & electrical conductivity
opaque, reflective.
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)
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Brittle, glassy, elastic
non-conducting (insulators)
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.
But:
Properties depend on Structure
(strength or hardness)
(d)
Hardness (BHN)
600
30 mm
500
(c)
400
(a)
(b)
4 mm
300
200
30 mm
100
0.01 0.1
And:
30 mm
1
10 100 1000
Cooling Rate (ºC/s)
Processing can change structure! (see
above structure vs Cooling Rate)
Another Example: Rolling of Steel
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At h1, L1
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low UTS
low YS
high ductility
round grains
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At h2, L2
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high UTS
high YS
low ductility
elongated grains
Structure determines Properties but Processing determines
Structure!
Optical Properties of Ceramic are
controlled
by “Grain Structure”
MAE 224: ENGINEERING MATERIALS
SINGLE
CRYSTAL
POLYCRYSTAL
POLYCRYSTAL
+ PORES
Figure 1.2 – Alumina (Al2O3) – single crystal and polycrystal
Grain Structure is a function of
“Solidification” processing!
1.Introduction
19
Electrical Properties (of Copper):
6
(10-8 Ohm-m)
Resistivity, r
5
4
Electrical Resistivity of
Copper is affected by:
3
• Contaminate level
• Degree of deformation
2
• Operating temperature
1
0
-200
-100
Adapted from Fig. 18.8, Callister 7e.
(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.)
0
T
(°C)
THERMAL Properties
• Space Shuttle Tiles:
• Thermal Conductivity
of Copper: --It decreases when
you add zinc!
Thermal Conductivity
(W/m-K)
--Silica fiber insulation
offers low heat conduction.
100 mm
Adapted from
Fig. 19.4W, Callister
6e. (Courtesy of
Lockheed Aerospace
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 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.)
MAGNETIC Properties
• Magnetic Storage:
vs. Composition:
--Adding 3 atomic % Si makes Fe a
better recording medium!
Magnetization
--Recording medium
is magnetized by
recording head.
• Magnetic Permeability
Fe+3%Si
Fe
Magnetic Field
Fig. 20.23, Callister 7e.
(Fig. 20.23 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, Inc.,
Upper Saddle River, New Jersey.
DETERIORATIVE Properties
• Stress & Saltwater...
• Heat treatment: slows
crack speed in salt water!
--causes cracks!
crack speed (m/s)
10-8
“as-is”
“held at
160ºC for 1 hr
before testing”
10-10
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:
Adapted from chapter-opening photograph,
Chapter 17, Callister 7e.
(from Marine Corrosion, Causes, and
Prevention, John Wiley and Sons, Inc., 1975.)
4 mm
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 Commercial
Airplane Company.)
Course Goal is to make you aware of the
importance of Material Selection by:
• 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.