1. CHAPTER 13: TYPES AND APPLICATONS OF MATERIALS
ISSUES TO ADDRESS...
• How are metal alloys classified and how are they used?
How do we classify ceramics?
What are some applications for ceramics? 1

2. Taxonomy of Metals Steels Cast Irons <1.4 wt% C 3-4.5 wt% C
Alloys
Steels
Ferrous
Nonferrous
Cast Irons Cu Al Mg Ti
<1.4wt%C
3-4.5
wt%C
Adapted from Fig. 11.1, Callister 7e.
Steels
<1.4 wt% C
Cast Irons
3-4.5 wt% C
microstructure:
ferrite, graphite
cementite Fe 3 C
cementite
1600
1400
1200
1000
800
600
400 1 2 4 5 6
6.7 L g
austenite +L
+Fe3C a
ferrite +
L+Fe3C d
(Fe)
Co , wt% C
Eutectic:
Eutectoid:
0.76
4.30
727°C
1148°C
T(°C)
Adapted from Fig. 9.24,Callister 7e. (Fig adapted from Binary Alloy Phase Diagrams, 2nd ed.,
Vol. 1, T.B. Massalski (Ed.-in-Chief), ASM International, Materials Park, OH, 1990.)

3. Steels Low Alloy High Alloy low carbon <0.25 wt% C Med carbon
high carbon
wt% C
plain
HSLA
heat
treatable
tool
austenitic
stainless
Name
Additions
none
Cr,V
Ni, Mo
Cr, Ni Mo
Cr, V,
Mo, W
Cr, Ni, Mo
Example
1010
4310
1040 43 40
1095
4190
304
Hardenability + ++
+++ TS - + ++ EL + + - - -- ++
Uses
auto
bridges
crank
pistons
wear
drills
high T
struc.
towers
shafts
gears
applic.
saws
applic.
sheet
press.
bolts
wear
dies
turbines
vessels
hammers
applic.
furnaces
increasing strength, cost, decreasing ductility
blades
V. corros.
resistant
Based on data provided in Tables 11.1(b), 11.2(b), 11.3, and 11.4, Callister 7e.

4. Ferrous Alloys Iron containing – Steels - cast irons
Nomenclature AISI & SAE
10xx Plain Carbon Steels
11xx Plain Carbon Steels (resulfurized for machinability)
15xx Mn (10 ~ 20%)
40xx Mo (0.20 ~ 0.30%)
43xx Ni ( %), Cr ( %), Mo ( %)
44xx Mo (0.5%)
where xx is wt% C x 100
example: steel – plain carbon steel with 0.60 wt% C
Stainless Steel -- >11% Cr

5. Cast Iron Ferrous alloys with > 2.1 wt% C
more commonly wt%C
low melting (also brittle) so easiest to cast
Cementite decomposes to ferrite + graphite
Fe3C  3 Fe () + C (graphite)
generally a slow process
So phase diagram for this system is different (Fig 12.4)

6. Fe-C True Equilibrium Diagram
1600
1400
1200
1000
800
600
400 1 2 3 4 90 L g +L
 + Graphite
Liquid +
Graphite
(Fe)
Co , wt% C
0.65
740°C
T(°C)
 + Graphite
100
1153°C
Austenite
4.2 wt% C
a + g
Graphite formation promoted by
Si > 1 wt%
slow cooling
Cast irons have graphite
Adapted from Fig. 11.2,Callister 7e. (Fig adapted from Binary Alloy Phase Diagrams, 2nd ed.,
Vol. 1, T.B. Massalski (Ed.-in-Chief), ASM International, Materials Park, OH, 1990.)

7. Types of Cast Iron Gray iron graphite flakes
weak & brittle under tension
stronger under compression
excellent vibrational dampening
wear resistant
Ductile iron
add Mg or Ce
graphite in nodules not flakes
matrix often pearlite - better ductility
Adapted from Fig. 11.3(a) & (b), Callister 7e.

8. Types of Cast Iron White iron <1wt% Si so harder but brittle
more cementite
Malleable iron
heat treat at ºC
graphite in rosettes
more ductile
Adapted from Fig. 11.3(c) & (d), Callister 7e.

9. Production of Cast Iron
Adapted from Fig.11.5, Callister 7e.

10. Limitations of Ferrous Alloys
Relatively high density
Relatively low conductivity
Poor corrosion resistance

11. Nonferrous Alloys NonFerrous Alloys • Cu Alloys • Al Alloys
Brass: Zn is subst. impurity
(costume jewelry, coins,
corrosion resistant)
Bronze
: Sn, Al, Si, Ni are
subst. impurity
(bushings, landing
gear)
Cu-Be :
precip. hardened
for strength
• Al Alloys
-lower r
: 2.7g/cm3
-Cu, Mg, Si, Mn, Zn additions
-solid sol. or precip.
strengthened (struct.
aircraft parts
& packaging)
NonFerrous
Alloys
• Mg Alloys
-very low r
: 1.7g/cm3
-ignites easily -
aircraft, missiles
• Ti Alloys
-lower r
: 4.5g/cm3
vs 7.9 for steel
-reactive at high T -
space applic.
• Refractory metals
-high melting T
-Nb, Mo, W, Ta
• Noble metals
-Ag, Au, Pt -
oxid./corr. resistant
Based on discussion and data provided in Section 11.3, Callister 7e.

12. TAXONOMY OF CERAMICS • Properties: • Applications: • Fabrication
Adapted from Fig and discussion in Section , Callister 6e.
• Properties:
--Tmelt for glass is moderate, but large for other ceramics.
--Small toughness, ductility; large moduli & creep resist.
• Applications:
--High T, wear resistant, novel uses from charge neutrality.
• Fabrication
--some glasses can be easily formed
--other ceramics can not be formed or cast. 5

13. Glass Structure • Basic Unit: • Glass is amorphous
• Amorphous structure
occurs by adding impurities
(Na+,Mg2+,Ca2+, Al3+)
• Impurities:
interfere with formation of
crystalline structure.
Si0 4
tetrahedron 4- Si 4+ O 2 -
• Quartz is crystalline
SiO2: Si 4+ Na + O 2 -
(soda glass)
Adapted from Fig , Callister, 7e.

14. Clay Composition A mixture of components used (50%) 1. Clay
(25%) 2. Filler – e.g. quartz (finely ground)
(25%) 3. Fluxing agent (Feldspar)
binds it together
aluminosilicates + K+, Na+, Ca+

15. Carbon Forms Carbon black – amorphous – surface area ca. 1000 m2/g
Diamond
tetrahedral carbon
hard – no good slip planes
brittle – can cut it
large diamonds – jewelry
small diamonds
often man made - used for cutting tools and polishing
diamond films
hard surface coat – tools, medical devices, etc.
(C likes to have covalent bonds & tetravalent)
Adapted from Fig , Callister 7e.

16. Carbon Forms - Graphite
layer structure – aromatic layers
weak van der Waal’s forces between layers
planes slide easily, good lubricant
Adapted from Fig , Callister 7e.
Like connected benzene rings

17. Carbon Forms – Fullerenes and Nanotubes
Fullerenes or carbon nanotubes
wrap the graphite sheet by curving into ball or tube
Buckminster fullerenes
Like a soccer ball C60 - also C70 + others
Adapted from Figs & 12.19, Callister 7e.

18. Polymers What is a polymer? Poly mer many repeat unit C H Cl C H H C
Polyethylene (PE) Cl C H
Polyvinyl chloride (PVC) H
Polypropylene (PP) C
CH3
Adapted from Fig. 14.2, Callister 7e.

19. Polymer Composition Most polymers are hydrocarbons
– i.e. made up of H and C
Saturated hydrocarbons
Each carbon bonded to four other atoms
CnH2n+2

20. Plastics Thermoplastic Polymers Thermosetting Polymers
Flexible linear chains
Thermosetting Polymers
고도로 cross-link된 polymer, 삼차원 망상구조, 강도/강성/경도 높으나 취성, 비가역반응: 재활용 문제

21. Polymer Types: Elastomers
Elastomers – rubber
Crosslinked materials
Natural rubber
Synthetic rubber and thermoplastic elastomers
SBR- styrene-butadiene rubber
styrene
butadiene
– Silicone rubber

22. <thermoplastic elastomer>
있는 경우
cross-linking 없는 경우

23. Polymer Types: Fibers Fibers - length/diameter >100
Textiles are main use
Must have high tensile strength
Usually highly crystalline & highly polar
Formed by spinning
ex: extrude polymer through a spinnerette
Pt plate with 1000’s of holes for nylon
ex: rayon – dissolved in solvent then pumped through die head to make fibers
the fibers are drawn
leads to highly aligned chains- fibrillar structure

24. Polymer Types Coatings – thin film on surface – i.e. paint, varnish
To protect item
Improve appearance
Electrical insulation
Adhesives – produce bond between two adherands
Usually bonded by:
Secondary bonds
Mechanical bonding
Films – blown film extrusion
Foams – gas bubbles in plastic

25. Advanced Polymers Ultrahigh molecular weight polyethylene (UHMWPE)
Molecular weight ca. 4 x 106 g/mol
Excellent properties for variety of applications
An extremely high impact resistance
Good resistance to wear and abrasion
Very low coefficient of friction
Excellent insulating properties
Bullet-proof vest, golf ball covers, hip joints, etc.
UHMWPE
Adapted from chapter-opening photograph, Chapter 22, Callister 7e.

26. SUMMARY Nonferrous: Basic categories of ceramics:
• Steels: increase TS, hardness (and cost) by adding
C (low alloy steels)
Cr, V, Ni, Mo, W (high alloy steels)
Ductility usually decreases w/ additions
Nonferrous:
Cu, Al, Ti, Mg Refractory, and noble metals
Basic categories of ceramics:
Glasses
Clay products
Refractories
Cements
Advanced ceramics 10

27. ANNOUNCEMENTS
Reading:
Core Problems:
Self-help Problems: