Fundamentals of Material Properties
Part 4- Common Engineering Materials
Darrell Wallace
Youngstown State University
2
Youngstown State University
January 14, 2006
Categories of Steel Alloys
Steel Alloys can be divided into five groups
Carbon Steels
High Strength Low Alloy Steels
Quenched and Tempered Steels
Heat Treatable Low Alloy Steels
Chromium-Molybdenum Steels





3
Youngstown State University
Steel
The American Iron and Steel Institute (AISI) defines carbon steel
as follows:
 Steel is considered to be carbon steel when no minimum
content is specified or required for chromium, cobalt,
columbium [niobium], molybdenum, nickel, titanium, tungsten,
vanadium or zirconium, or any other element to be added to
obtain a desired alloying effect; when the specified minimum
for copper does not exceed 0.40 per cent; or when the
maximum content specified for any of the following elements
does not exceed the percentages noted: manganese 1.65,
silicon 0.60, copper 0.60. Carbon steels are normally classified
as shown below.
4
Youngstown State University
Steel – Low Carbon
Low-carbon steels contain up to 0.30 weight percent C. The
largest category of this class of steel is flat-rolled products
(sheet or strip) usually in the cold-rolled and annealed
condition. The carbon content for these high-formability steels
is very low, less than 0.10 weight percent C, with up to 0.4
weight percent Mn. For rolled steel structural plates and
sections, the carbon content may be increased to
approximately 0.30 weight percent, with higher manganese up
to 1.5 weight percent.

5
Youngstown State University
Steel – Medium / High Carbon
Medium-carbon steels are similar to low-carbon steels
except that the carbon ranges from 0.30 to 0.60 weight
percent and the manganese from 0.60 to 1.65 weight percent.
Increasing the carbon content to approximately 0.5 weight
percent with an accompanying increase in manganese allows
medium-carbon steels to be used in the quenched and
tempered condition.
High-carbon steels contain from 0.60 to 1.00 weight
percent C with manganese contents ranging from 0.30 to
0.90weight percent.


6
Youngstown State University
Steel – High-Strength Low Alloy
High-strength low-alloy (HSLA) steels, or microalloyed
steels, are designed to provide better mechanical properties
than conventional carbon steels. They are designed to meet
specific mechanical properties rather than a chemical
composition. The chemical composition of a specific HSLA
steel may vary for different product thickness to meet
mechanical property requirements. The HSLA steels have low
carbon contents (0.50 to ~0.25 weight percent C) in order to
produce adequate formability and weldability, and they have
manganese contents up to 2.0 weight percent. Small quantities
of chromium, nickel, molybdenum, copper, nitrogen, vanadium,
niobium, titanium, and zirconium are used in various
combinations.

7
Youngstown State University
Steel Alloy Designations
AISI Designations for Steel Alloys
Carbon Steels
10xx
11xx
12xx
Manganese steels
13xx
Nickel steels
23xx
25xx
Nickel Chromium Steels
31xx
32xx
33xx
34xx
Chromium Molybdenum steels
41xx
Plain Carbon
Resulfurized
Resulfurized and
rephosphorized
Nickel Chromium Molybdenum
steels
43xx
Mn 1.75
47xx
Ni 3.5
Ni 5.0
86xx
Cr 0.50-0.95 Mo 0.120.30
Ni 1.82 Cr 0.50-0.80
Mo 0.25
Ni 1.05 Cr 0.45 Mo
0.20 – 0.35
Ni 0.55 Cr 0.50 Mo
0.20
Nickel Molybdenum steels
Ni 1.25 Cr 0.65-0.80
Ni 1.75 Cr 1.07
Ni 3.50 Cr 1.50-1.57
Ni 3.00 Cr 0.77
46xx
48xx
Chromium steels
50xx
51xx
Ni 0.85-1.82 Mo 0.20
Ni 3.50 Mo 0.25
Cr 0.27- 0.65
Cr 0.80 – 1.05
http://www.materialsengineer.com/E-Alloying-Steels.htm
8
Youngstown State University
Effects of Steel Alloying Elements
•Carbon has a major effect on steel properties. Carbon is the primary
hardening element in steel. Hardness and tensile strength increases as
carbon content increases up to about 0.85% C as shown in the figure
above. Ductility and weldability decrease with increasing carbon.
•Manganese is generally beneficial to surface quality especially in
resulfurized steels. Manganese contributes to strength and hardness, but
less than carbon. The increase in strength is dependent upon the carbon
content. Increasing the manganese content decreases ductility and
weldability, but less than carbon. Manganese has a significant effect on the
hardenability of steel.
•Phosphorus increases strength and hardness and decreases ductility and
notch impact toughness of steel. The adverse effects on ductility and
toughness are greater in quenched and tempered higher-carbon
steels. Phosphorous levels are normally controlled to low levels. Higher
phosphorus is specified in low-carbon free-machining steels to improve
machinability.
9
Youngstown State University
Effects of Steel Alloying Elements
•Sulfur decreases ductility and notch impact toughness especially in the
transverse direction. Weldability decreases with increasing sulfur
content. Sulfur is found primarily in the form of sulfide inclusions. Sulfur
levels are normally controlled to low levels. The only exception is freemachining steels, where sulfur is added to improve machinability.
•Silicon is one of the principal deoxidizers used in steelmaking. Silicon is
less effective than manganese in increasing as-rolled strength and
hardness. In low-carbon steels, silicon is generally detrimental to surface
quality.
•Copper in significant amounts is detrimental to hot-working steels. Copper
negatively affects forge welding, but does not seriously affect arc or
oxyacetylene welding. Copper can be detrimental to surface quality. Copper
is beneficial to atmospheric corrosion resistance when present in amounts
exceeding 0.20%. Weathering steels are sold having greater than 0.20%
Copper.
10
Youngstown State University
Effects of Steel Alloying Elements
•Lead is virtually insoluble in liquid or solid steel. However, lead is
sometimes added to carbon and alloy steels by means of mechanical
dispersion during pouring to improve the machinability.
•Boron is added to fully killed steel to improve hardenability. Boron-treated
steels are produced to a range of 0.0005 to 0.003%. Whenever boron is
substituted in part for other alloys, it should be done only with hardenability
in mind because the lowered alloy content may be harmful for some
applications.
•Boron is a potent alloying element in steel. A very small amount of boron
(about 0.001%) has a strong effect on hardenability. Boron steels are
generally produced within a range of 0.0005 to 0.003%. Boron is most
effective in lower carbon steels.
11
Youngstown State University
Effects of Steel Alloying Elements
•Chromium is commonly added to steel to increase corrosion resistance
and oxidation resistance, to increase hardenability, or to improve hightemperature strength. As a hardening element, Chromium is frequently used
with a toughening element such as nickel to produce superior mechanical
properties. At higher temperatures, chromium contributes increased
strength. Chromium is a strong carbide former. Complex chromium-iron
carbides go into solution in austenite slowly; therefore, sufficient heating
time must be allowed for prior to quenching.
•Nickel is a ferrite strengthener. Nickel does not form carbides in steel. It
remains in solution in ferrite, strengthening and toughening the ferrite
phase. Nickel increases the hardenability and impact strength of steels.
•Molybdenum increases the hardenability of steel. Molybdenum may
produce secondary hardening during the tempering of quenched steels. It
enhances the creep strength of low-alloy steels at elevated temperatures.
12
Youngstown State University
Effects of Steel Alloying Elements
•Aluminum is widely used as a deoxidizer. Aluminum can control austenite
grain growth in reheated steels and is therefore added to control grain
size. Aluminum is the most effective alloy in controlling grain growth prior
to quenching. Titanium, zirconium, and vanadium are also valuable grain
growth inhibitors, but there carbides are difficult to dissolve into solution in
austenite.
•Zirconium can be added to killed high-strength low-alloy steels to achieve
improvements in inclusion characteristics. Zirconium causes sulfide
inclusions to be globular rather than elongated thus improving toughness
and ductility in transverse bending.
•Niobium (Columbium) increases the yield strength and, to a lesser degree,
the tensile strength of carbon steel. The addition of small amounts of
Niobium can significantly increase the yield strength of steels. Niobium can
also have a moderate precipitation strengthening effect. Its main
contributions are to form precipitates above the transformation temperature,
and to retard the recrystallization of austenite, thus promoting a fine-grain
microstructure having improved strength and toughness.
13
Youngstown State University
Effects of Steel Alloying Elements
•Titanium is used to retard grain growth and thus improve toughness.
Titanium is also used to achieve improvements in inclusion
characteristics. Titanium causes sulfide inclusions to be globular rather
than elongated thus improving toughness and ductility in transverse
bending.
•Vanadium increases the yield strength and the tensile strength of carbon
steel. The addition of small amounts of Vanadium can significantly increase
the strength of steels. Vanadium is one of the primary contributors to
precipitation strengthening in microalloyed steels. When
thermomechanical processing is properly controlled the ferrite grain size is
refined and there is a corresponding increase in toughness. The impact
transition temperature also increases when vanadium is added.
•All microalloy steels contain small concentrations of one or more strong
carbide and nitride forming elements. Vanadium, niobium, and titanium
combine preferentially with carbon and/or nitrogen to form a fine dispersion
of precipitated particles in the steel matrix.
14
Youngstown State University
Stainless Steels

General Information Stainless steels are high-alloy
steels that have superior corrosion resistance than other
steels because they contain large amounts of chromium.
Stainless steels can contain anywhere from 4-30 percent
chromium, however most contain around 10 percent.
Stainless steels can be divided into three basic groups
based on their crystalline structure: austenitic, ferritic,
and martensitic. Another group of stainless steels
known as precipitation-hardened steels are a combination
of austenitic and martensitic steels.
http://www.efunda.com/materials/alloys/stainless_steels/stainless.cfm
15
Youngstown State University
Stainless Steels

Ferritic grades: Ferritic stainless steels are magnetic
non heat-treatable steels that contain chromium but not
nickel. They have good heat and corrosion resistance, in
particular sea water, and good resistance to stresscorrosion cracking. Their mechanical properties are not
as strong as the austenitic grades, however they have
better decorative appeal.
http://www.efunda.com/materials/alloys/stainless_steels/stainless.cfm
16
Youngstown State University
Stainless Steels

Martensitic grades: Martensitic grades are magnetic
and can be heat-treated by quenching or tempering. They
contain chromium but usually contain no nickel, except
for 2 grades. Martensitic steels are not as corrosive
resistant as austenitic or ferritic grades, but their
hardness levels are among the highest of the all the
stainless steels.
http://www.efunda.com/materials/alloys/stainless_steels/stainless.cfm
17
Youngstown State University
Stainless Steels

Austenitic grades: Austenitic stainless steels are nonmagnetic non heat-treatable steels that are usually annealed
and cold worked. Some austenitic steels tend to become
slightly magnetic after cold working. Austenitic steels have
excellent corrosion and heat resistance with good mechanical
properties over a wide range of temperatures. There are two
subclasses of austenitic stainless steels: chromium-nickel and
chromium-manganese-low nickel steels. Chromium-nickel
steels are the most general widely used steels and are also
known as 18-8(Cr-Ni) steels. The chromium nickel ratio can be
modified to improve formability; carbon content can be
reduced to improve intergranular corrosion resistance.
Molybdenum can be added to improve corrosion resistance;
additionally the Cr-Ni content can be increased.
18
Youngstown State University
http://www.efunda.com/materials/alloys/stainless_steels/stainless.cfm
Tool Steels

Tool steels typically have excess carbides (carbon alloys) which
make them hard and wear-resistant. Most tool steels are used
in a heat-treated state, generally hardened and tempered.
There are a number of categories assigned by AISI (American
Iron and Steel Institute), each with an identifying letter:
W: Water-Hardening
S: Shock-Resisting
O: Cold-Work (Oil-Hardening)
A: Cold-Work (Medium-Alloy, AirHardening)
D: Cold-Work (High-Carbon, HighChromium)
L: Low-Alloy F: Carbon-Tungsten
19
P:
P1-P19: Low-Carbon Mold Steels
P20-P39: Other Mold Steels
H:
H1-H19: Chromium-Base Hot Work
H20-H29: Tungsten-Base Hot Work
H40-H59: Molybdenum-Base Hot Work
T: High-Speed (Tungsten-Base)
M: High-Speed (Molybdenum-Base)
Youngstown State University
Aluminum – General Information

Aluminum is a silverish white metal that has a strong
resistance to corrosion and like gold, is rather malleable.
It is a relatively light metal compared to metals such as
steel, nickel, brass, and copper with a specific gravity of
2.7. Aluminum is easily machinable and can have a wide
variety of surface finishes. It also has good electrical and
thermal conductivities and is highly reflective to heat and
light.
20
Youngstown State University
Aluminum - Characteristics

At extremely high temperatures (200-250°C) aluminum alloys tend to lose some of their
strength. However, at subzero temperatures, their strength increases while retaining their
ductility, making aluminum an extremely useful low-temperature alloy. Aluminum alloys
have a strong resistance to corrosion which is a result of an oxide skin that forms as a
result of reactions with the atmosphere. This corrosive skin protects aluminum from most
chemicals, weathering conditions, and even many acids, however alkaline substances are known
to penetrate the protective skin and corrode the metal.

Aluminum also has a rather high electrical conductivity, making it useful as a conductor.
Copper is the more widely used conductor, having a conductivity of approximately 161% that
of aluminum. Aluminum connectors have a tendency to become loosened after repeated usage
leading to arcing and fire, which requires extra precaution and special design when using
aluminum wiring in buildings.

Aluminum is a very versatile metal and can be cast in any form known. It can be rolled,
stamped, drawn, spun, roll-formed, hammered and forged. The metal can be extruded into a
variety of shapes, and can be turned, milled, and bored in the machining process. Aluminum can
riveted, welded, brazed, or resin bonded. For most applications, aluminum needs no protective
coating as it can be finished to look good, however it is often anodized to improve color and
strength.
21
Youngstown State University
Aluminum Alloy Designations
Designati
on
Major Alloying Element
1xxx
Unalloyed (pure) >99% Al
2xxx
Copper is the principal alloying element, though
other elements (Magnesium) may be specified
3xxx
Manganese is the principal alloying element
4xxx
Silicon is the principal alloying element
5xxx
Magnesium is the principal alloying element
6xxx
Magnesium and Silicon are principal alloying
elements
7xxx
Zinc is the principal alloying element, but other
elements such as Copper, Magnesium, Chromium,
and Zirconium may be specified
8xxx
Other elements (including Tin and some Lithium
compositions)
9xxx
Reserved for future use
http://www.materialsengineer.com/E-Aluminum.htm
22
Youngstown State University
Aluminum Alloy Characteristics
1xxx Series. These grades of aluminum are characterized by excellent corrosion
resistance, high thermal and electrical conductivities, low mechanical properties,
and excellent workability. Moderate increases in strength may be obtained by
strain hardening. Iron and silicon are the major impurities.
2xxx Series. These alloys require solution heat treatment to obtain optimum
properties; in the solution heat-treated condition, mechanical properties are
similar to, and sometimes exceed, those of low-carbon steel. In some instances,
precipitation heat treatment (aging) is employed to further increase mechanical
properties. This treatment increases yield strength, with attendant loss in
elongation; its effect on tensile strength is not as great. The alloys in the 2xxx
series do not have as good corrosion resistance as most other aluminum alloys,
and under certain conditions they may be subject to intergranular
corrosion. Alloys in the 2xxx series are good for parts requiring good strength at
temperatures up to 150 °C (300 °F). Except for alloy 2219, these alloys have
limited weldability, but some alloys in this series have superior machinability.
http://www.materialsengineer.com/E-Aluminum.htm
23
Youngstown State University
Aluminum Alloy Characteristics
3xxx Series. These alloys generally are non-heat treatable but have about 20%
more strength than 1xxx series alloys. Because only a limited percentage of
manganese (up to about 1.5%) can be effectively added to aluminum,
manganese is used as major element in only a few alloys.
4xxx Series. The major alloying element in 4xxx series alloys is silicon, which
can be added in sufficient quantities (up to 12%) to cause substantial lowering of
the melting range. For this reason, aluminum-silicon alloys are used in welding
wire and as brazing alloys for joining aluminum, where a lower melting range than
that of the base metal is required. The alloys containing appreciable amounts of
silicon become dark gray to charcoal when anodic oxide finishes are applied and
hence are in demand for architectural applications.
http://www.materialsengineer.com/E-Aluminum.htm
24
Youngstown State University
Aluminum Alloy Characteristics
7xxx Series. Zinc, in amounts of 1 to 8% is the major alloying element in 7xxx
series alloys, and when coupled with a smaller percentage of magnesium results
in heat-treatable alloys of moderate to very high strength. Usually other elements,
such as copper and chromium, are also added in small quantities. 7xxx series
alloys are used in airframe structures, mobile equipment, and other highly
stressed parts. Higher strength 7xxx alloys exhibit reduced resistance to stress
corrosion cracking and are often utilized in a slightly overaged temper to provide
better combinations of strength, corrosion resistance, and fracture toughness.
http://www.materialsengineer.com/E-Aluminum.htm
25
Youngstown State University
Copper Alloys
Copper alloys are commonly used for their electrical and thermal conductivities, corrosion
resistance, ease of fabrication, surface appearance, strength and fatigue resistance. Copper
alloys can be readily soldered and brazed, and a number of copper alloys can be welded by
arc, and resistance methods. Color of copper alloys is a significant reason for using them for
decorative purposes. For decorative parts, conventional copper alloys having specific colors
are readily available.
Copper is used extensively for cables and wires, electrical contacts, and a wide variety of
other parts that are required to pass electrical current. Coppers alloys are used for automobile
radiators, heat exchangers, and home heating systems. Because of copper alloys corrosion
resistance they are used for pipes, valves, and fittings in systems carrying potable water,
process water, or other aqueous fluids.
Along with ease of fabrication, some of the principal selection criteria for copper alloys are:
• Corrosion resistance
• Electrical conductivity
• Thermal conductivity
• Color and surface appearance
26
Youngstown State University
Copper Alloys
Corrosion resistance of copper alloys is good in many environments, however
copper alloys may be attacked by some common reagents and environments. Pure
copper resists attack under some corrosive conditions. Some copper alloys, on the
other hand, sometimes have inadequate performance in certain environments.
Stress corrosion cracking most commonly occurs in brass. Brasses containing
more than 15% Zn are the most susceptible.
Dealloying is another form of corrosion that affects zinc containing copper
alloys. During dezincification of brass, selective removal of zinc results in gradual
replacement of sound brass by weak, porous copper. Unless stopped the metal is
weakened and liquids or gases may be capable of leaking through the porous
structure.
Electrical and thermal conductivity of copper and its alloys are relatively good. This
is why copper is the most commonly used electrical conductor. Alloying decreases
electrical conductivity to a greater extent than thermal conductivity. This is why
copper and high-copper alloys are preferred over other copper alloys when high
electrical or thermal conductivity is required.
27
Youngstown State University
Common Copper Alloys
Name
Coppers
Brasses
Leaded brasses
Tin brasses
Phosphor bronzes
Leaded phosphor bronzes
Copper-phosphorus and copper-silverphosphorus alloys
Aluminum bronzes
Silicon bronzes
Copper-nickels
Nickel silvers
28
Alloying elements
Cu
Cu-Zn
Cu-Zn-Pb
Cu-Zn-Sn-Pb
Cu-Sn-P
Cu-Sn-Pb-P
Cu-P-Ag
Cu-Al-Ni-Fe-Si-Sn
Cu-Si-Sn
Cu-Ni-Fe
Cu-Ni-Zn
Youngstown State University
Resistance Properties of Common Copper Alloys
Alloy
r
a
Notes
Pure Cu
1.67
0.00404
Electrolytic
Cu
1.71
0.00397
ETP Copper
Oxygen Free
Cu
1.71
N/A
OF Copper
1.0% Pb
1.76
N/A
Free
Machining
Copper
5% Zn
3.1
0.00231
Gilding Metal
15% Zn
4.7
0.00160
Red Brass
30% Zn
6.2
0.00148
Cartridge
Brass
35% Zn
6.4
N/A
Yellow Brass
5% Sn
11
N/A
Phosphor
Bronze
30% Ni
37
0.00048
Cupro Nickel
mW*cm
1/K
20C
http://www.gbint.com/Files/Apps/Alloy%20Table/Alloy%20Table.htm
29
Youngstown State University
Titanium






Titanium Alloys
The density of Titanium is roughly 55% that of steel. Titanium alloys are extensively utilized
for significantly loaded aerospace components. Titanium is used in applications requiring
somewhat elevated temperatures . The good corrosion resistance experienced in many
environments is based on titanium’s ability to form a stable oxide protective layer. This makes
titanium useful in surgical implants and some chemical plant equipment applications.
Unalloyed (commercially pure) titanium can be found in two crystallographic forms:
Hexagonal close-packed (hcp) or alpha (α) phase is found at room temperature
Body centered cubic (bcc) or beta (ß) phase is found above 883 °C (1621 °F)
The control of alpha (α) and beta (ß) phases through alloying additions and thermomechanical
processing is the basis for the titanium alloys used by industry today. It is also the primary
method for classifying titanium alloys. Titanium alloys are categorized as either alpha (α)
alloys, beta (ß) alloys, or alpha+beta (α+ß) alloys.
One of the primary effect of alloying
elements used in titanium production is the affect on the alpha to beta transformation
temperature. Some elements raise the alpha to beta transformation temperature thereby
stabilizing the alpha crystal structure. While other elements lower the alpha to beta
transformation temperature thereby stabilizing the beta crystal structure. The effect of some
elements is shown below:
30
Youngstown State University
http://www.materialsengineer.com/E-Titanium.htm
Titanium







One of the primary effect of alloying elements used in titanium production is the affect on the alpha to
beta transformation temperature. Some elements raise the alpha to beta transformation temperature
thereby stabilizing the alpha crystal structure. While other elements lower the alpha to beta
transformation temperature thereby stabilizing the beta crystal structure. The effect of some elements is
shown below:
Element Effect Aluminum alpha stabilizer Tin alpha stabilizer Vanadium Beta
stabilizer Molybdenum Beta stabilizer Chromium
Beta stabilizer Copper
Beta stabilizer Alpha alloys commonly have creep resistance superior to beta alloys. Alpha alloys are
suitable for somewhat elevated temperature applications. They are also sometimes used for cryogenic
applications. Alpha alloys have adequate strength, toughness, and weldability for various applications, but are
not as readily forged as many beta alloys. Alpha alloys cannot be strengthened by heat treatment.
Beta alloys have good forging capability. Beta alloy sheet is cold formable when in the solution treated
condition. Beta alloys are prone to a ductile to brittle transition temperature. Beta alloys can be
strengthened by heat treatment. Typically beta alloys are solutioned followed by aging to form finely
dispersed particles in a beta phase matrix.
Alpha + beta alloys have chemical compositions that result in a mixture of alpha and beta phases. The beta
phase is normally in the range of 10 to 50% at room temperature. Alloys with beta contents less than 20%
are weldable. The most commonly used titanium alloy is Ti-6Al-4V, an alpha + beta alloy. While Ti-6Al-4V is
fairly difficult to form other alpha + beta alloys normally have better formability.
Alpha + beta alloys can be strengthened by heat treatment. When strengthening alpha + beta alloys the
components are normally quickly cooled from a temperature high in the alpha-beta range or even above
the beta transus. Solution treatment is then followed by aging to generate an proper mixture of alpha and
transformed beta. Heat treatment is dependent on the cooling rate from the solution temperature and can
be affected by the size of the component.
31
Youngstown State University
http://www.materialsengineer.com/E-Titanium.htm
Titanium
Some of the uses of titanium alloys:







32
Surgical Implants
Prosthetic devices
Jet engines
Chemical processing plants
Pulp and paper industry
Marine applications
Sports equipment
Youngstown State University
http://www.materialsengineer.com/E-Titanium.htm
Unified Numbering System (UNS)
UNS Series
A00001 to A99999
C00001 to C99999
D00001 to D99999
Metal
Aluminum and aluminum alloys
Copper and copper alloys
Specified mechanical property steels
E00001 to E99999
Rare earth and rare earthlike metals and alloys
F00001 to F99999
H00001 to H99999
J00001 to J99999
K00001 to K99999
L00001 to L99999
Cast irons
AISI and SAE carbon and alloy steels (except tool
steels)
AISI and SAE H-steels
Cast steels (except tool steels)
Miscellaneous steels and ferrous alloys
Low-melting metals and alloys
M00001 to M99999
Miscellaneous nonferrous metals and alloys
N00001 to N99999
P00001 to P99999
Nickel and nickel alloys
Precious metals and alloys
R00001 to R99999
Reactive and refractory metals and alloys
S00001 to S99999
Heat and corrosion resistant (stainless) steels
T00001 to T99999
W00001 to W99999
Z00001 to Z99999
Tool steels, wrought and cast
Welding filler metals
Zinc and zinc alloys
G00001 to G99999
http://www.materialsengineer.com/E-UNS-designations.htm
33
Youngstown State University
Polymer Vocabulary















additive Any substance that is added to a plastic during manufacturing in order to improve its properties.
butyl A type of elastomer that is often used to make airtight products.
chloroprene A type of elastomer that effectively resists oil, weather, heat, and flame. Chloroprene was one the first
successful synthetic rubbers.
cross-linking The development of primary bonds that form between polymer molecules. Elastomers are slightly cross-linked;
thermosets are heavily cross-linked.
elastomer A formation of a thermoplastic or thermoset that can stretch and then return to its original shape without
permanent deformation. Elastomers are only slightly cross-linked.
Filler An additive that is used to partially replace a plastic material and reduce its cost.
macromolecule An incredibly large molecule that consists of repeating molecular units.
mer The basic molecular unit that combines in long chains to form polymers.
molecule The smallest unit into which a material can be divided without changing its properties. A molecule consists of a
group of atoms held together by strong primary bonds.
natural polymer A polymer resulting from raw materials found in nature.
natural rubber A natural elastomer that is extracted as a sap from tropical trees. Natural rubber must be vulcanized for
commercial use.
phenolic A type of thermoset known for its chemical stability and ability to maintain its desired dimensions.
plastic A material consisting of very large molecules characterized by light weight, high corrosion resistance, high strengthto-weight ratios, and low melting points. Most plastics are easily shaped or formed. plasticizer An additive that is used to
add softness and flexibility to a plastic in order to facilitate the manufacturing process.
Polyester A type of thermoset that is commonly combined with other polymers for numerous commercial uses.
rubber.
http://www.toolingu.com/class_class_desc.aspx?class_ID=500240
34
Youngstown State University
Polymer Vocabulary

polyethylene A type of thermoplastic known for being both chemically inert and inexpensive. Polyethylene is the most popular commercial plastic.

polymer A material made of very large molecules that generally does not have a crystalline structure. Polymer is a more technical term for a plastic.

polypropylene A type of thermoplastic known for being very lightweight.

polystyrene A type of thermoplastic that is both transparent and easily shaped.

polyurethane A type of plastic that is often chemically complex. Polyurethane can be manufactured as both a thermoset and an elastomer.

polyvinyl chloride A type of thermoplastic that can be manufactured to produce both rigid and flexible materials.

primary bond A bond that forms between atoms and that involves the exchanging or sharing of electrons.

secondary bond A bond that involves attraction between molecules. Unlike primary bonding, there is no transfer or sharing of electrons.

shellac A resinous substance secreted from a particular beetle that is used to coat floors and furniture. Shellac is a natural polymer.

silicone A type of thermoset known for being both heat resistant and water repellant.

stabilizer An additive that is used to help prevent a plastic from breaking down due to exposure to adverse environments.

steel A metal consisting of iron and up to 2.11% carbon, usually with small amounts of manganese, phosphorus, sulfur, and silicon as well.

strength-to-weight ratio The relationship between a material's strength and its weight. Materials that are light but also very strong have a high
strength-to-weight ratio.

synthetic polymer A polymer that is chemically manufactured from separate materials. Synthetic polymers require human intervention.

thermal conductivity The ability of a material to conduct heat.

thermoplastic A type of plastic that can be softened by heat, hardened by cooling, and then softened by heat over and over again. Thermoplastics
are not cross-linked.

thermoset A type of plastic that is permanently hardened by cooling. Thermosets are heavily cross-linked.

vulcanization A manufacturing process that uses additives and chemicals along with heat and pressure to increase the number of cross-linked bonds
in an elastomer. Vulcanization adds strength and toughness to a rubber.
http://www.toolingu.com/class_class_desc.aspx?class_ID=500240
35
Youngstown State University
Epoxy

Epoxy has been mass-produced since 1946. - It is a thermoset polyadduct. Applications: Used in reactive molding compounds. Also used in adhesives. General properties: It is air curable, highly fillable, possesses low shrinkage
and low susceptibility to stress formation. Good adhesion to almost all
materials. High tensile and vibrational strength. High heat resistance, high
heat deformation resistance, and high chemical attack resistance. Good
aging properties. Good electrical and dielectrical properties. Odorless,
tasteless, low flammability. Systems can be formulated to meet specific
requirements. - Trade Name: Acme, Aerolam, Basoset, Beckopx, Conapoxy,
Corlar, Cycom, DER, Desmobond, Dobeckot, Dynopon, Ecco, Epikote, Epocast,
Epodite, Eprosin, Eurepox, Exatron, Grilonit, Hysol, Isochembond, Lekutherm,
Lopox, Nikalet, Paraplex, Quartrex, Scotchcast, Synthane.
http://www.efunda.com/materials/polymers
36
Youngstown State University
PTFE (Teflon)

Fluoroplastics, also known as PTFE, or FEP, PFA, CTFE,
ECTFE, ETFE, has been mass-produced since 1950. - It is
a thermoplastic polymer. - Applications: Used in applications
needing excellent dielectric strength, chemical, and
temperature resistance. - General properties: It has low
mechanical strength and is expensive.Very low coefficient
of friction. - Trade Name: Teflon.
http://www.efunda.com/materials/polymers
37
Youngstown State University
Phenol-formaldehyde (Phenolic)

Phenol-formaldehyde Plastic, also known as PF, or
Phenolic, has been mass-produced since 1909. - It is a
thermoset polycondensate. - Applications: The first volumeproduced synthesized polymer resin, PF was used in early
consumer electronic products such as telephones and
radios. - General properties: A naturally brittle material in
pure form, it is able to be strengthened with fillers such as
wood pulp and cellulose. - Trade Name: Bakelite.
http://www.efunda.com/materials/polymers
38
Youngstown State University
Polyamide (Nylon)

Polyamide, also known as PA, or Nylon, has been massproduced since 1935. - It is a thermoplastic
polycondensate. - Applications: Used to make high-lubricity
parts (e.g. bearings, blow moldings, and clothing fabric). General properties: It has high lubricity and moderate
strength. It is tough, inexpensive, and has poor
dimensional stability due to water absorption
(hygroscopic nature). - Trade Name: Ultramid, Zytel.
http://www.efunda.com/materials/polymers
39
Youngstown State University
Polycarbonate (Lexan)

Polycarbonate, also known as PC, has been massproduced since 1958. - It is a thermoplastic
polycondensate. - Applications: Used to make optical lenses,
windows, medical items, CD's, and power tool housings.
Also used in truck cabs. - General properties: It has
excellent strength and toughness. It possesses good
dimensional stability, dielectric strength, flame retardancy,
and impact resistance (highest among transparent rigid
materials). It is susceptible to stress cracking with
aromatic solvents, and is difficult to machine. - Trade
Name: Lexan, Makrolon.
http://www.efunda.com/materials/polymers
40
Youngstown State University
Polyethylene

Polyethylene, also known as PE, has been massproduced since 1939. - It is a thermoplastic polymer. Applications: The largest volume commodity plastic, PE is
used in blow-molded beverage bottles, auto gas tanks, and
extruded pipe. - General properties: It has good
toughness at low temperatures and is inexpensive. - Trade
Name: Marlex, Alathon, Hostalen.
http://www.efunda.com/materials/polymers
41
Youngstown State University
Polyurethane

Polyurethane, also known as PU, has been massproduced since 1940. - It is a thermoplastic or thermoset,
(typically reinforced), polyadduct. - Applications: Used in
automotive structural members, computer housings,
furniture, and packaging foams. - General properties: It has
high impact resistance, dielectric strength, chemical
resistance, and abrasion resistance. It can be made into
films, solid moldings, or flexible foams. Becomes brittle
with outdoor exposure. - Trade Name: Estane, Pellanthane.
http://www.efunda.com/materials/polymers
42
Youngstown State University
Silicone

Silicone, also known as SI, has been mass-produced
since 1943. - It is a thermoset polycondensate. Applications: Used in computer chips, IC, cooking ware,
and food containers. - General properties: It possesses
dimensional stability and good electrical and dielectrical
properties over wide frequency and temperature ranges.
It has flame resistance, low water absorption, moderate
thermal shock resistance, and average polymeric
mechanical properties. It has a high cost, limited shelf-life,
and a long curing time. - Trade Name: Baysilon, Blu-Sil,
Commex, Fiberite, Lamitex, Siltemp,Textolite.
http://www.efunda.com/materials/polymers
43
Youngstown State University