Transcript Engr 2110 Introduction to Material Science (for Engineers)
Introduction to Material Science
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 …
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 – agent ( “ glue ” ) fixing must avoid any debris in cup Must hold up in body chemistry Must be strong yet flexible
Acetabular Cup and Liner Femoral Stem Ball
Types of Materials
Major Types of Materials
METALS CERAMICS POLYMERS
Other Materials
COMPOSITES ELECTRONIC MATERIALS ADVANCED MATERIALS
Materials
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.
• Some of these have descriptive subclasses.
• Classes have overlap, so some materials fit into more than one class.
• Metals • Iron and Steel • Alloys and Superalloys ( e.g. aerospace applications) • Intermetallic Compounds (high-T structural materials) • Ceramics • Structural Ceramics ( high-temperature load bearing) • Refractories (corrosion-resistant, insulating) • Whitewares (e.g. porcelains) • Glass • Electrical Ceramics (capacitors, insulators, transducers, etc.) • Chemically Bonded Ceramics (e.g. cement and concrete) 11
• Polymers • Plastics • Liquid crystals • Adhesives • Composites • Particulate composites ( small particles embedded in a different material) • Laminate composites (golf club shafts, tennis rackets, Damaskus swords) • Fiber reinforced composites (e.g. fiberglass) • Electronic Materials • Silicon and Germanium • III-V Compounds ( e.g. GaAs) • Photonic materials (solid-state lasers, LEDs) • Biomaterials (really using previous 5, but bio-mimetic) • Man-made proteins ( cytoskeletal protein rods or “artificial bacterium”) • Biosensors (Au-nanoparticles stabilized by encoded DNA for anthrax detection) • Drug-delivery colloids (polymer based) 12
Thoughts about these
“
fundamental
”
Materials
Metals :
Strong, ductile high thermal & electrical conductivity opaque, reflective.
Polymers/plastics : Covalent bonding
Soft, ductile, low strength, low density thermal & electrical insulators Optically translucent or transparent.
sharing of e ’ s
Ceramics : ionic bonding (refractory) nitrides, sulfides) – compounds of metallic & non-metallic elements (oxides, carbides,
Brittle, glassy, elastic non-conducting (insulators)
The Materials Selection Process
1.
2.
Pick Application Determine required Properties Properties: mechanical, electrical, thermal, magnetic, optical, deteriorative.
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.
ASHBY “ Strength-Density ” Material Selection Diagram
15
Detailed diagram for Metals Detailed diagram for ceramics
16
ASHBY “ Strength-Ductility ” Material Selection Diagram
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ASHBY “ Strength-Cost ” Material Selection Diagram
18
Properties of Materials (ex: Strength or Hardness, etc.) Depend on Structure
(d) Example: 1080 Steel 600 500 400 (a) 300 200 30 m m (b) 30 m m (c) 4 m m 30 m m 100 0.01 0.1
1 10 100 1000 Cooling Rate (ºC/s) And: Processing can change structure! (see above structure vs Cooling Rate)
Another Example: Rolling of Steel
At h 1 , L 1
low UTS
low YS
high ductility round grains
At h 2 , L 2
high UTS
high YS
low ductility elongated grains
Structure determines Properties but Processing Structure !
determines
Optical Properties of Ceramic are controlled by “Grain Structure”
MAE 224: ENGINEERING MATERIALS SINGLE CRYSTAL POLYCRYSTAL POLYCRYSTAL + PORES Figure 1.2 – Alumina (Al 2 O 3 ) – single crystal and polycrystal
Grain Structure is a function of
1.Introduction 19
Electrical Properties (of Copper):
6 5 4 3 2 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) 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!
400 300 200 100 Adapted from Fig. 19.4W,
Callister 6e.
(Courtesy of Lockheed Aerospace Ceramics Systems, Sunnyvale, CA) (Note: "W" denotes fig. is on CD-ROM.) 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.) 100 m m
MAGNETIC Properties
• Magnetic Storage : --Recording medium is magnetized by recording head.
• Magnetic Permeability vs. Composition: --Adding 3 atomic % Si makes Fe a better recording medium!
Fe+3%Si Fe Fig. 20.23,
Callister 7e.
(Fig. 20.23 is from J.U. Lemke,
MRS Bulletin
, Vol. XV, No. 3, p. 31, 1990.) Magnetic Field 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...
--causes cracks! Adapted from chapter-opening photograph, Chapter 17,
Callister 7e.
(from
Marine Corrosion, Causes, and Prevention
, John Wiley and Sons, Inc., 1975.) • Heat treatment: slows crack speed in salt water!
10 -8 10 -10 “as-is” “held at 160ºC for 1 hr before testing” 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: 4 m m 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.)
Courses on Materials Science will 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.