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Chapter 1 - 1
Chapter 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?
Polymer Age?
Chapter 1 - 2
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.
Chapter 1 - 3
Example Hip Implant
Requirements
mechanical strength (many cycles)
good lubricity
biocompatibility
Adapted from Fig. 22.24, Callister 7e.
Chapter 1 - 4
Example Hip Implant
Adapted from Fig. 22.26, Callister 7e.
BlackTypewriterHistorically, development and advancement of societies have been intimately tied to the members ability to produce and manipulate materials to fill their needs. In fact, early civilizations have been designated by the level of their materials development (Bronze, Steel, Iron)
BlackTypewriterThe earliest humans had access to only a very limited number of materials, those that occur naturally: stone, wood, clay, skins, and so on. With time they discovered techniques for producing materials that had properties superior to those of the natural ones. Furthermore, it was discovered that the properties of a material could be altered by heat treatments and by the addition of other substances. At this point, materials utilization was totally a selection process that involved deciding from a given, rather limited set of materials the one best suited for an application by virtue of its characteristics
BlackTypewriter
BlackTypewriterAt this point, materials utilization was totally a selection process that involved deciding from a given, rather limited set of materials the one best suited for an application by virtue of its characteristics.
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Chapter 1 - 5
Hip Implant
Key problems to overcome
fixation agent to hold acetabular cup
cup lubrication material
femoral stem fixing agent
must avoid any debris in cup
Femoral Stem
Ball
AcetabularCup and Liner
Adapted from chapter-opening photograph, Chapter 22, Callister 7e. (Photograph courtesy of Zimmer, Inc., Warsaw, IN, USA.)
Chapter 1 - 6
Example Develop New Types of Polymers
Commodity plastics large volume ca. $0.50 / lbEx. Polyethylene
PolypropylenePolystyreneetc.
Engineering Resins small volume > $1.00 / lbEx. Polycarbonate
NylonPolysulfoneetc.
Can polypropylene be upgraded to properties (and price) near those of engineering resins?
Chapter 1 - 7
ex: hardness vs structure of steel Properties depend on structure
Data obtained from Figs. 10.31(a) and 10.32 with 4 wt% C composition, and from Fig. 11.15, Callister & Rethwisch 9e. Micrographs adapted from (a) Fig. 10.19; (b) Fig. 9.30; (c) Fig. 10.33; and (d) Fig. 10.21, Callister & Rethwisch 9e. (Figures 10.19, 10.21, & 10.33 copyright 1971 by United States Steel Corporation. Figure 9.30 courtesy of Republic Steel Corporation.)
ex: structure vs cooling rate of steel Processing can change structure
Structure, Processing, & Properties
Ha
rdn
ess
(B
HN
)
Cooling Rate (C/s)
100
200
300
400
500
600
0.01 0.1 1 10 100 1000
(d)
30m(c)
4m
(b)
30m
(a)
30m
Chapter 1 - 8
Types of Materials Metals:
Strong, ductile
High thermal & electrical conductivity
Opaque, reflective.
Polymers/plastics: Covalent bonding sharing of electrons 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)
BlackHighlight
BlackTypewriterMaterials Science involves investigating the relationships that exist between the structures and properties of materials. Materials Engineering is, on the basis of these structureproperty correlations, designing or engineering the structure of a material to produce a predetermined set of properties.
BlackTypewriterProcessing:Structure:Properties:Performance:
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Chapter 1 - 9
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 - 10
ELECTRICAL
Electrical Resistivity of Copper:
Adding impurity atoms to Cu increases resistivity.
Deforming Cu increases resistivity.
Fig. 18.8, Callister & Rethwisch 9e. [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
1
2
3
4
5
6
Re
sis
tivity,
(10
-8O
hm
-m)
0
Chapter 1 - 11
THERMAL Space Shuttle Tiles:
-- Silica fiber insulationoffers low heat conduction.
Thermal Conductivityof Copper:-- It decreases when
you add zinc!
Fig. 19.4W, Callister 6e. (Courtesy of Lockheed Aerospace Ceramics Systems, Sunnyvale, CA)(Note: "W" denotes fig. is on CD-ROM.)
Fig. 19.4, Callister & Rethwisch 9e. [Adapted from Metals Handbook: Properties and Selection: Nonferrous alloys and Pure Metals, Vol. 2, 9th ed., H. Baker, (Managing Editor), ASM International, 1979, p. 315.]
Composition (wt% Zinc)
The
rma
l C
ond
uct
ivity
(W
/m-K
)
400
300
200
100
00 10 20 30 40
100m
Chapter-opening photograph, Chapter 17, Callister & Rethwisch 3e. (Courtesy of LockheedMissiles and SpaceCompany, Inc.)
Chapter 1 - 12
MAGNETIC Magnetic Permeability
vs. Composition:-- Adding 3 atomic % Si
makes Fe a betterrecording medium!
Adapted from C.R. Barrett, W.D. Nix, andA.S. Tetelman, The Principles of EngineeringMaterials, Fig. 1-7(a), p. 9, 1973.Electronically reproduced by permission of Pearson Education, Inc., Upper Saddle River, New Jersey.
Fig. 20.23, Callister & Rethwisch 9e.(Courtesy of HGST, a Western Digital Company.)
Magnetic Storage:-- Recording medium
is magnetized byrecording head.
Magnetic Field
Magnetiz
atio
n Fe+3%Si
Fe
BlackHighlight
BlackTypewriterProcessing -> Structure -> Properties -> Performance
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Chapter 1 - 13
Transmittance:-- Aluminum oxide may be transparent, translucent, or
opaque depending on the materials structure (i.e., single crystal vs. polycrystal, and degree of porosity).
Fig. 1.2, Callister & Rethwisch 9e.(Specimen preparation,P.A. Lessing)
single crystalpolycrystal:no porosity
polycrystal:some porosity
OPTICAL
Chapter 1 - 14
DETERIORATIVE Stress & Saltwater...
-- causes cracks!
Fig. 17.21, Callister & Rethwisch 9e. (from Marine Corrosion, Causes, and Prevention, John Wiley and Sons, Inc., 1975.)
Heat treatment: slowscrack 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
160C for 1 hr
before testing
increasing load
cra
ck s
pe
ed
(m
/s) as-is
10-10
10-8
Alloy 7178 tested in
saturated aqueous NaCl
solution at 23C
Chapter 1 - 15
Use the right material for the job.
Understand the relation between properties,structure, and processing.
Recognize new design opportunities offeredby materials selection.
Course Goals:
SUMMARY