1
1
Materials Science - Introduction
What is materials science?
understanding relationship between stucture and properies
What is materials engineering?
designing the structure to produce a predetermined set of properties
Main problem: selecting the right material from the many thousands that
are available
Two other important components: processing and performance
2
2
1. Pick Application Determine required Properties
2. Properties Identify candidate Material(s)
3. Material Identify required Processing
Processing: changes structure and overall shape
ex: casting, sintering, vapor deposition, doping
forming, joining, annealing.
Material: structure, composition.
The Materials Selection Process
3
3
Process-Propery Interaction
Processing
method
Micro-
structure
Property
Engineers make things. They make them out of materials. The materials
have to support loads, to insulate or conduct heat and electricity, etc.
To make sth. out material you need also a process. Not just any process –
the one you choose has to be compatible with the material you plan to use.
processing-structure-properties-performance
• Material of all three disks -> Aluminum Oxide
• Left Disk -> a single crystal
• Center Disk ->composed of numerous and very small single crystals
that are all connected
• Right Disk ->composed of many small, interconnected crystals, and
large number of small pores or void spaces
4
5
Periodic Table
IA VIIIA
1 2
H He
1.008 IIA IIIA IVA VA VIA VIIA 4.003
3 4 5 6 7 8 9 10
Li Be B C N O F Ne
6.941 9.012 10.81 12.01 14.01 15.99 19 20.18
11 12 13 14 15 16 17 18
Na Mg Al Si P S Cl Ar
22.99 24.31 IIIB IVB VB VIB VIIB VIIIB IB IIB 26.98 28.09 30.97 32.07 35.45 39.94
19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
39.1 40.08 44.96 47.88 50.94 52 54.94 55.85 58.93 58.69 63.55 65.39 69.72 72.61 74.92 78.96 79.9 83.8
37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54
Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe
85.47 87.62 88.91 91.22 92.91 95.94 -98 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3
55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 85 86
Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn
132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 192.2 195.1 197 200.6 204.4 207.2 209 (209) (210) (222)
87 88 89
Fr Ra Ac
(223) 226 227
58 59 60 61 62 63 64 65 66 67 68 69 70 71
Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
140.1 140.9 144.2 (145) 150.4 152 157.3 158.9 162.5 164.9 167.3 168.9 173 175
90 91 92 93 94 95 96 97 98 99 100 101 102 103
Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr
232 231 238 237 (244) (243) (247) (247) (251) (252) (257) (258) (259) (260)
Classification of Materials
Figure I.2 An outline of the engineering materials described in Part I
.
New advanced
materials
Nanomaterials,
shape-memory
alloys
superconductors
semiconductors
…
6
7
7
METALS
• Relatively dense
• Stiff
• Strong
• Ductile
• Resistant to fracture
• Good conductors of heat and electricity
• Not transparent to visible light
• Some of them magnetic
9
9
CERAMICS
• Relatively stiff
• Strong
• Very hard
• Extremely brittle
• Susceptible to fracture
• Insulative to heat and electricity
• Resistant to high temperature
• May be transparent,translucent or opaque
Compounds
between metallic
and nonmetallic
elements
10
10
POLYMERS
• Low density
• Not as stiff and strong as metals
• May be ductile
• May be pliable (easily formed into complex
shapes)
• Unreactive in most environments
• Low conductivityofheat and electricity
• Tendency to soften and decomposed with
temperature
A Polymer at Macroscopic Level
Appearance of real linear polymer chains as recorded using an atomic force microscope on
surface under liquid medium. Chain contour length for this polymer is ~204 nm; thickness is
~0.4 nm
11
12
12
EXAMPLES OF POLYMERS
• Polyethylen (PE)
• Nylon
• Polyvinyl chloride (PCV)
• Polycarbonate (PC)
• Polystyrene (PS|)
• Silicon rubber
COMPOSITES
• Composites are engineered materials made from two or more
constituent materials with significantly different physical or chemical
properties, which remain separate and distinct on a macroscopic
level within the finished structure
COMPOSITES (contd…)
• The design goal of a composite is to achieve a combination of
properties that is not displayed by any single material
• Some naturally-occurring materials are also considered to be
composites
• One of the common composites is fiberglass, in which small glass
fibers are embedded within a polymeric material
• Glass Fiber -> Strong + Stiff + Brittle
• Polymer -> Ductile + Weak + Flexible
14
Glass-Fiber Reinforced Polymer
15
COMPOSITES (contd…)
• CFRP -> carbon fibers that are embedded within a polymer
• These materials are stiffer and stronger than the glass fiber-
reinforced materials, thus they are more expensive
• CFRPs are used in some aircraft and aerospace applications, as well as
high-tech sporting equipment
16
Advanced Materials
• Materials that are utilized in high-tech applications
• Hi-Tech -> device or product that operates or functions using
relatively intricate and sophisticated principles
• These advanced materials are typically traditional materials whose
properties have been enhanced, and, also newly developed, high-
performance materials.
• include semiconductors, biomaterials, and materials of the future
(i.e., smart materials and nanoengineered materials)
17
1. Semiconductors
• Semiconductors have electrical properties that are
intermediate between the conductors (e.g. metals and metal
alloys) and insulators (e.g. ceramics and polymers)
• Common semiconducting materials are crystalline solids but
amorphous and liquid semiconductors are known. These
include hydrogenated amorphous silicon and mixtures of
arsenic, selenium and tellurium in a variety of proportions
• Electrical characteristics are extremely sensitive to the
presence of minute concentrations of impurity atoms
• Semiconductors have caused the advent of integrated
circuitry
18
2. Biomaterials
• A biomaterial is any material, natural or man-made, that comprises
whole or part of a living structure or biomedical device which
performs, augments, or replaces a natural function
• must not produce toxic substances and must be compatible with
body tissues
• All of the above materials—metals, ceramics, polymers, composites,
and semiconductors—may be used as biomaterials
• Examples -> Artificial hip, bone plates, heart valves, contact lenses,
dental implants, etc
19
Materials of the Future – Smart Materials
• Smart materials are materials that have one or more properties that
can be significantly changed in a controlled fashion by external
stimuli, such as stress, temperature, moisture, pH, electric or
magnetic fields
• Smart material (or system) include some type of sensor, and an
actuator
• Four types -> shape memory alloys, piezoelectric ceramics,
magnetostrictive materials, and
electrorheological/magnetorheological fluids
20
Smart Materials (contd…)
• Shape Memory Alloys -> alloy that "remembers" its original shape
and returns the pre-deformed shape by heating
• Main types of shape memory alloys are the copper-zinc-aluminum-
nickel, copper-aluminum-nickel, and nickel-titanium
• Piezoelectric ceramics -> produce a voltage when stress is applied.
Since this effect also applies in the reverse manner, a voltage across
the sample will produce stress within the sample
• Magnetostrictive materials -> analogous to piezoelectrics, except
that they are responsive to magnetic fields
• Electrorheological and Magnetorheological fluids -> liquids that
experience dramatic changes in viscosity upon the application of
electric and magnetic fields, respectively
• Materials for sensors -> Optical fibers, Piezoelectrics,
Microelectromechanical devices
21
Materials of the Future – Nanoengineered
Materials
• It has become possible to manipulate and move atoms and
molecules to form new structures and design new materials
that are built from simple atomic-level constituents
• This ability to carefully arrange atoms provides opportunities
to develop mechanical, electrical, magnetic, and other
properties that are not otherwise possible
• One example of a material of this type is the carbon
nanotube
22
• The definition of the nanocomponents
materials: are materials that are made
based on different components
“nanometric scale worked” .
• For instance, take nanoclay, to reinforce
plastics,
• Carbon Nanotubes as well are used to
provide conductivity to another
materials.
Carbon nanotubes
Nanoclay
23
Distinction criteria
•Mechanical
•Physical
•Optical
•Chemical
•Electrical
•…
• Endurance
• Aucostical
• Surface
• Electrochemical
• …
25
25
MECHANICAL
• Strength
• Stiffness
• Hardness
• Ductility
• Toughness
• Wear resistance
• Fatigue resistance
• Creep resistance
Displayed when a force
is applied to a material
Comparison Chart- 2
Bar-chart of room temperature stiffness (elastic modulus)
26
Comparison Chart- 3
Bar-chart of room temperature strength (tensile strength)
27
Comparison Chart- 4
Bar-chart of room temperature resistance to fracture (fracture
toughness)
28
Physical Properties
• Density
• Melting point
• Specific heat
• Heat conduction coefficient
• Thermal expansion coefficient
• Electrical conduction
• Dielectric constant
• Magnetic permeability
• Color
• Transparency
• …
29
Comparison Chart- 1
Bar-chart of room temperature density
30
31
Comparison Chart- 5
Bar-chart of room temperature electrical conductivity ranges
32
33
33
ELECTRICAL
• Electrical Resistivity of Copper:
• Adding “impurity” atoms to Cu increases resistivity.
• Deforming Cu increases resistivity.
The electrical resistivity
versus temperature for
copper and three copper–
nickel alloys, one of which
has been deformed.
Thermal, impurity, and
deformation contributions
to the resistivity are
indicated at -100C.
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
Resistivity,
r
(10
-8
Ohm-m)
0
Cu + 1.12 at%Ni
“Pure” Cu
34
34
Transmittance:
Aluminum oxide may
be transparent,
translucent, or
opaque depending on
the material structure.
single crystal
polycrystal:
low porosity
polycrystal:
high porosity
OPTICAL
35
35
THERMAL
Thermal Conductivity of Copper:
- It decreases when you add zinc!
Composition (wt% Zinc)
Thermal
Conductivity
(W/m-K)
400
300
200
100
0
0 10 20 30 40
Thermal diffusivity differs from the
conductivity because materials
differ in their heat capasity.
36
36
MAGNETIC
Magnetic Permeability vs. Composition:
Adding 3 atomic % Si makes Fe a better
recording medium!
Schematic representation showing
how information is stored and
retrieved using a magnetic storage
medium.
Magnetic Storage:
- Recording medium
is magnetized by
recording head.
Magnetic Field
Magnetization
Fe+3%Si
Fe
Chemical Properties
37
– Oxidation
– Corrosion
– Flammability
– Toxicity
– Reactivity
– …
38
38
DETERIORATIVE
• Stress & Saltwater...
--causes cracks!
Photograph showing a bar of steel
that has been bent into a ‘‘horseshoe’’
shape using a nut-and-bolt assembly.
While immersed in seawater, stress
corrosion cracks formed along the
bend at those regions where the
tensile stresses are the greatest.
4 mm
7150-T651 Al alloy
(Zn,Cu,Mg,Zr)
• Heat treatment: slows
crack speed in salt water!
“held at
160ºC for 1 hr
before testing”
increasing load
crack
speed
(m/s)
“as-is”
10 -10
10 -8
Alloy 7178 tested in
saturated aqueous NaCl
solution at 23ºC
39
39
Classes of Process
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!
Material selection
43
44
Figure 1.8 Polymers are
used in a variety of
electronic devices,
including these computer
dip
switches, where moisture
resistance and low
conductivity are required.
(Courtesy of CTS
Corporation.)
Figure 1.9 Integrated
circuits for computers and
other electronic devices
rely on the unique
electrical behavior of
semiconducting materials.
(Courtesy of Rogers
Corporation.)
Figure 1.10 The X-wing for
advanced helicopters relies
on a material composed of a
carbon-fiber-
reinforced polymer.
(Courtesy of Sikorsky Aircraft
Division—United
Technologies
Corporation.)
Engineering materials applications
45
Figure 1-14 Schematic of a X-33 plane prototype. Notice the use of different
materials for different parts. This type of vehicle will test several components for
the Venturestar (From ‘‘A Simpler Ride into Space,’’ by T.K. Mattingly, October,
1997, Scientific American, p. 125. Copyright © 1997 Slim Films.)
47
47
p02_pg1
CARBONATED BEVERAGE CONTAINERS
ceramic (glass)
polymer (plastic)
metal (aluminum)
Constraints:
• provide a barier to the passage of carbon
dioxide, which is under pressure in the
container
• be nontoxic, unreactive with the beverage,
and, preferably be recyclabe
• be relatively strong, and capable of surviving
a drop from a height of several meters when
containing the beverage
• be inexpensive and the cost to fabricate the
final shape should be relatively low
• if optically transparent, retain its optical clarity
• capable of being produce having different
colors and/or able to be adorned with
decorative labels

material selection for marin products 1 .pptx

  • 1.
    1 1 Materials Science -Introduction What is materials science? understanding relationship between stucture and properies What is materials engineering? designing the structure to produce a predetermined set of properties Main problem: selecting the right material from the many thousands that are available Two other important components: processing and performance
  • 2.
    2 2 1. Pick ApplicationDetermine required Properties 2. Properties Identify candidate Material(s) 3. Material Identify required Processing Processing: changes structure and overall shape ex: casting, sintering, vapor deposition, doping forming, joining, annealing. Material: structure, composition. The Materials Selection Process
  • 3.
    3 3 Process-Propery Interaction Processing method Micro- structure Property Engineers makethings. They make them out of materials. The materials have to support loads, to insulate or conduct heat and electricity, etc. To make sth. out material you need also a process. Not just any process – the one you choose has to be compatible with the material you plan to use.
  • 4.
    processing-structure-properties-performance • Material ofall three disks -> Aluminum Oxide • Left Disk -> a single crystal • Center Disk ->composed of numerous and very small single crystals that are all connected • Right Disk ->composed of many small, interconnected crystals, and large number of small pores or void spaces 4
  • 5.
    5 Periodic Table IA VIIIA 12 H He 1.008 IIA IIIA IVA VA VIA VIIA 4.003 3 4 5 6 7 8 9 10 Li Be B C N O F Ne 6.941 9.012 10.81 12.01 14.01 15.99 19 20.18 11 12 13 14 15 16 17 18 Na Mg Al Si P S Cl Ar 22.99 24.31 IIIB IVB VB VIB VIIB VIIIB IB IIB 26.98 28.09 30.97 32.07 35.45 39.94 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr 39.1 40.08 44.96 47.88 50.94 52 54.94 55.85 58.93 58.69 63.55 65.39 69.72 72.61 74.92 78.96 79.9 83.8 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 Rb Sr Y Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te I Xe 85.47 87.62 88.91 91.22 92.91 95.94 -98 101.1 102.9 106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3 55 56 57 72 73 74 75 76 77 78 79 80 81 82 83 85 86 Cs Ba La Hf Ta W Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn 132.9 137.3 138.9 178.5 180.9 183.9 186.2 190.2 192.2 195.1 197 200.6 204.4 207.2 209 (209) (210) (222) 87 88 89 Fr Ra Ac (223) 226 227 58 59 60 61 62 63 64 65 66 67 68 69 70 71 Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu 140.1 140.9 144.2 (145) 150.4 152 157.3 158.9 162.5 164.9 167.3 168.9 173 175 90 91 92 93 94 95 96 97 98 99 100 101 102 103 Th Pa U Np Pu Am Cm Bk Cf Es Fm Md No Lr 232 231 238 237 (244) (243) (247) (247) (251) (252) (257) (258) (259) (260)
  • 6.
    Classification of Materials FigureI.2 An outline of the engineering materials described in Part I . New advanced materials Nanomaterials, shape-memory alloys superconductors semiconductors … 6
  • 7.
    7 7 METALS • Relatively dense •Stiff • Strong • Ductile • Resistant to fracture • Good conductors of heat and electricity • Not transparent to visible light • Some of them magnetic
  • 8.
    9 9 CERAMICS • Relatively stiff •Strong • Very hard • Extremely brittle • Susceptible to fracture • Insulative to heat and electricity • Resistant to high temperature • May be transparent,translucent or opaque Compounds between metallic and nonmetallic elements
  • 9.
    10 10 POLYMERS • Low density •Not as stiff and strong as metals • May be ductile • May be pliable (easily formed into complex shapes) • Unreactive in most environments • Low conductivityofheat and electricity • Tendency to soften and decomposed with temperature
  • 10.
    A Polymer atMacroscopic Level Appearance of real linear polymer chains as recorded using an atomic force microscope on surface under liquid medium. Chain contour length for this polymer is ~204 nm; thickness is ~0.4 nm 11
  • 11.
    12 12 EXAMPLES OF POLYMERS •Polyethylen (PE) • Nylon • Polyvinyl chloride (PCV) • Polycarbonate (PC) • Polystyrene (PS|) • Silicon rubber
  • 12.
    COMPOSITES • Composites areengineered materials made from two or more constituent materials with significantly different physical or chemical properties, which remain separate and distinct on a macroscopic level within the finished structure
  • 13.
    COMPOSITES (contd…) • Thedesign goal of a composite is to achieve a combination of properties that is not displayed by any single material • Some naturally-occurring materials are also considered to be composites • One of the common composites is fiberglass, in which small glass fibers are embedded within a polymeric material • Glass Fiber -> Strong + Stiff + Brittle • Polymer -> Ductile + Weak + Flexible 14
  • 14.
  • 15.
    COMPOSITES (contd…) • CFRP-> carbon fibers that are embedded within a polymer • These materials are stiffer and stronger than the glass fiber- reinforced materials, thus they are more expensive • CFRPs are used in some aircraft and aerospace applications, as well as high-tech sporting equipment 16
  • 16.
    Advanced Materials • Materialsthat are utilized in high-tech applications • Hi-Tech -> device or product that operates or functions using relatively intricate and sophisticated principles • These advanced materials are typically traditional materials whose properties have been enhanced, and, also newly developed, high- performance materials. • include semiconductors, biomaterials, and materials of the future (i.e., smart materials and nanoengineered materials) 17
  • 17.
    1. Semiconductors • Semiconductorshave electrical properties that are intermediate between the conductors (e.g. metals and metal alloys) and insulators (e.g. ceramics and polymers) • Common semiconducting materials are crystalline solids but amorphous and liquid semiconductors are known. These include hydrogenated amorphous silicon and mixtures of arsenic, selenium and tellurium in a variety of proportions • Electrical characteristics are extremely sensitive to the presence of minute concentrations of impurity atoms • Semiconductors have caused the advent of integrated circuitry 18
  • 18.
    2. Biomaterials • Abiomaterial is any material, natural or man-made, that comprises whole or part of a living structure or biomedical device which performs, augments, or replaces a natural function • must not produce toxic substances and must be compatible with body tissues • All of the above materials—metals, ceramics, polymers, composites, and semiconductors—may be used as biomaterials • Examples -> Artificial hip, bone plates, heart valves, contact lenses, dental implants, etc 19
  • 19.
    Materials of theFuture – Smart Materials • Smart materials are materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli, such as stress, temperature, moisture, pH, electric or magnetic fields • Smart material (or system) include some type of sensor, and an actuator • Four types -> shape memory alloys, piezoelectric ceramics, magnetostrictive materials, and electrorheological/magnetorheological fluids 20
  • 20.
    Smart Materials (contd…) •Shape Memory Alloys -> alloy that "remembers" its original shape and returns the pre-deformed shape by heating • Main types of shape memory alloys are the copper-zinc-aluminum- nickel, copper-aluminum-nickel, and nickel-titanium • Piezoelectric ceramics -> produce a voltage when stress is applied. Since this effect also applies in the reverse manner, a voltage across the sample will produce stress within the sample • Magnetostrictive materials -> analogous to piezoelectrics, except that they are responsive to magnetic fields • Electrorheological and Magnetorheological fluids -> liquids that experience dramatic changes in viscosity upon the application of electric and magnetic fields, respectively • Materials for sensors -> Optical fibers, Piezoelectrics, Microelectromechanical devices 21
  • 21.
    Materials of theFuture – Nanoengineered Materials • It has become possible to manipulate and move atoms and molecules to form new structures and design new materials that are built from simple atomic-level constituents • This ability to carefully arrange atoms provides opportunities to develop mechanical, electrical, magnetic, and other properties that are not otherwise possible • One example of a material of this type is the carbon nanotube 22
  • 22.
    • The definitionof the nanocomponents materials: are materials that are made based on different components “nanometric scale worked” . • For instance, take nanoclay, to reinforce plastics, • Carbon Nanotubes as well are used to provide conductivity to another materials. Carbon nanotubes Nanoclay 23
  • 23.
  • 24.
    25 25 MECHANICAL • Strength • Stiffness •Hardness • Ductility • Toughness • Wear resistance • Fatigue resistance • Creep resistance Displayed when a force is applied to a material
  • 25.
    Comparison Chart- 2 Bar-chartof room temperature stiffness (elastic modulus) 26
  • 26.
    Comparison Chart- 3 Bar-chartof room temperature strength (tensile strength) 27
  • 27.
    Comparison Chart- 4 Bar-chartof room temperature resistance to fracture (fracture toughness) 28
  • 28.
    Physical Properties • Density •Melting point • Specific heat • Heat conduction coefficient • Thermal expansion coefficient • Electrical conduction • Dielectric constant • Magnetic permeability • Color • Transparency • … 29
  • 29.
    Comparison Chart- 1 Bar-chartof room temperature density 30
  • 30.
  • 31.
    Comparison Chart- 5 Bar-chartof room temperature electrical conductivity ranges 32
  • 32.
    33 33 ELECTRICAL • Electrical Resistivityof Copper: • Adding “impurity” atoms to Cu increases resistivity. • Deforming Cu increases resistivity. The electrical resistivity versus temperature for copper and three copper– nickel alloys, one of which has been deformed. Thermal, impurity, and deformation contributions to the resistivity are indicated at -100C. 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 Resistivity, r (10 -8 Ohm-m) 0 Cu + 1.12 at%Ni “Pure” Cu
  • 33.
    34 34 Transmittance: Aluminum oxide may betransparent, translucent, or opaque depending on the material structure. single crystal polycrystal: low porosity polycrystal: high porosity OPTICAL
  • 34.
    35 35 THERMAL Thermal Conductivity ofCopper: - It decreases when you add zinc! Composition (wt% Zinc) Thermal Conductivity (W/m-K) 400 300 200 100 0 0 10 20 30 40 Thermal diffusivity differs from the conductivity because materials differ in their heat capasity.
  • 35.
    36 36 MAGNETIC Magnetic Permeability vs.Composition: Adding 3 atomic % Si makes Fe a better recording medium! Schematic representation showing how information is stored and retrieved using a magnetic storage medium. Magnetic Storage: - Recording medium is magnetized by recording head. Magnetic Field Magnetization Fe+3%Si Fe
  • 36.
    Chemical Properties 37 – Oxidation –Corrosion – Flammability – Toxicity – Reactivity – …
  • 37.
    38 38 DETERIORATIVE • Stress &Saltwater... --causes cracks! Photograph showing a bar of steel that has been bent into a ‘‘horseshoe’’ shape using a nut-and-bolt assembly. While immersed in seawater, stress corrosion cracks formed along the bend at those regions where the tensile stresses are the greatest. 4 mm 7150-T651 Al alloy (Zn,Cu,Mg,Zr) • Heat treatment: slows crack speed in salt water! “held at 160ºC for 1 hr before testing” increasing load crack speed (m/s) “as-is” 10 -10 10 -8 Alloy 7178 tested in saturated aqueous NaCl solution at 23ºC
  • 38.
  • 39.
    Another Example: Rollingof 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!
  • 40.
  • 41.
    44 Figure 1.8 Polymersare used in a variety of electronic devices, including these computer dip switches, where moisture resistance and low conductivity are required. (Courtesy of CTS Corporation.) Figure 1.9 Integrated circuits for computers and other electronic devices rely on the unique electrical behavior of semiconducting materials. (Courtesy of Rogers Corporation.) Figure 1.10 The X-wing for advanced helicopters relies on a material composed of a carbon-fiber- reinforced polymer. (Courtesy of Sikorsky Aircraft Division—United Technologies Corporation.) Engineering materials applications
  • 42.
    45 Figure 1-14 Schematicof a X-33 plane prototype. Notice the use of different materials for different parts. This type of vehicle will test several components for the Venturestar (From ‘‘A Simpler Ride into Space,’’ by T.K. Mattingly, October, 1997, Scientific American, p. 125. Copyright © 1997 Slim Films.)
  • 44.
    47 47 p02_pg1 CARBONATED BEVERAGE CONTAINERS ceramic(glass) polymer (plastic) metal (aluminum) Constraints: • provide a barier to the passage of carbon dioxide, which is under pressure in the container • be nontoxic, unreactive with the beverage, and, preferably be recyclabe • be relatively strong, and capable of surviving a drop from a height of several meters when containing the beverage • be inexpensive and the cost to fabricate the final shape should be relatively low • if optically transparent, retain its optical clarity • capable of being produce having different colors and/or able to be adorned with decorative labels

Editor's Notes

  • #4 a photograph showing three thin disk specimens placed over some printed matter. It is obvious that the optical properties (i.e., the light transmittance) of each of the three materials are different; the one on the left is transparent (i.e., virtually all of the reflected light passes through it), whereas the disks in the center and on the right are, respectively, translucent (allowing light to pass through diffusely) and opaque. that is, it is highly perfect—which gives rise to its transparency … the boundaries between these small crystals scatter a portion of the light reflected from the printed page, which makes this material optically translucent These pores also effectively scatter the reflected light and render this material opaque The structures of these three specimens are different in terms of crystal boundaries and pores, which affect the optical transmittance properties. Furthermore, each material was produced using a different processing technique. And, of course, if optical transmittance is an important parameter relative to the ultimate in-service application, the performance of each material will be different.
  • #11 Y. Roiter and S. Minko, AFM Single Molecule Experiments at the Solid-Liquid Interface: In Situ Conformation of Adsorbed Flexible Polyelectrolyte Chains, Journal of the American Chemical Society, vol. 127, iss. 45, pp. 15688-15689 (2005).
  • #13 The constituent materials come from the categories discussed above—viz., metals, ceramics, and polymers LEFT -> Glass/carbon/aramid fibres with thermoset/thermoplastic resins RIGHT -> single-walled nanotubes (yellow) bundle together when used as the reinforcing element of a composite material. The nanotubes are depicted at the interface with the polymer polyethylene (individual polymer molecules are shown in different shades of blue).
  • #14 … and also to incorporate the best characteristics of each of the component materials. … —e.g., wood and bone. However, most of those we consider in our discussions are synthetic (or man-made) composites … normally an epoxy or polyester. Thus, the resulting fiberglass is relatively stiff, strong, flexible, and ductile. In addition, it has a low density
  • #16 Another of these technologically important materials is the “carbon fiber reinforced polymer … . e.g., bicycles, golf clubs, tennis rackets, and skis/snowboards
  • #17 2. Examples include electronic equipment (camcorders, CD/DVD players, etc.), computers, fiber-optic systems, spacecraft, aircraft, and military rocketry 3. … they may be of all material types (e.g., metals, ceramics, polymers), and are normally expensive
  • #18 1. A semiconductor is a material that has an electrical conductivity due to flowing electrons (as opposed to ionic conductivity) 3. … for which the concentrations may be controlled over very small spatial regions. Amorphous -> without real or apparent crystalline form 4. … that has totally revolutionized the electronics and computer industries (not to mention our lives) over the past three decades.
  • #19 Biomaterials are employed in components implanted into the human body for replacement of diseased or damaged body parts … i.e., must not cause adverse biological reactions
  • #20 that will have a significant influence on many of our technologies. … Term “smart” implies that these materials are able to sense changes in their environments and then respond to these changes in predetermined manners— traits that are also found in living organisms Sensor (that detects an input signal); Actuator (that performs a responsive and adaptive function)… …. Actuators may be called upon to change shape, position, natural frequency, or mechanical characteristics in response to changes in temperature, electric fields, and/or magnetic fields
  • #21 metals that, after having been deformed, revert back to their original shapes when temperature is changed … The large deformation results due to martensitic phase change (pseudoelasticity) . Piezoelectric ceramics expand and contract in response to an applied electric field (or voltage); conversely, they also generate an electric field when their dimensions are altered
  • #22 with the advent of scanning probe microscopes, which permit observation of individual atoms and molecules … the “nano” prefix denotes that the dimensions of these structural entities are on the order of a nanometer (10e-9 m) m)—as a rule, less than 100 nanometers (equivalent to approximately 500 atom diameters)
  • #30 GFRC -> Glass Fiber Reinforced Concrete CFRC -> Carbon Fiber Reinforced Composite PTFE -> poly tetra fluoro ethylene PS -> Poly styrene PE -> Poly ethylene