|
Here is a list of all
of the material groups currently considered by the MAS (click on
a name to get more information for that group).
Complete listings begin
here:
|
Name
|
Density
|
Low
Yield Strength
|
High
Yield Strength
|
Cost
per Weight
|
| Cast
Iron |
450
lb/ft^3
|
14
ksi
|
125
ksi
|
0.68
$/lb
|
| Cast
Iron, aside from the ubiquitous skillet, is often a brittle
material, so casting processes are prefered.
Other
products using cast iron include: clutch plates, brake drums,
machine tool support structures (for cast irons good damping
characteristics), wheel hubs, gears, rollers, valve bodies,
pump housings, and a variety of decorative applications.
|
| Carbon
Steel |
487
lb/ft^3
|
43
ksi
|
152
ksi
|
0.454
$/lb
|
| This
category contains the bulk of the steel products manufactured.
There is a plentiful supply, but it lacks corrosion resistance
unless treated (galvanizing, a good coat of paint, etc).
Typical
applications include: Automobile panels, nails, wire, pipe,
structural members (I-beams), sheets, pressure vessels, crankshafts,
bolts, chisels, hammers, saws, knives.
|
| Alloy
Steel |
487
lb/ft^3
|
103
ksi
|
270
ksi
|
9.07
$/lb
|
| By
including a variety of other elements in the basic iron / carbon
makeup, a variety of very hard and wear resistant alloys can
be made.
Typical
applications: Springs, hand tools, bushings, aircraft tubing,
shafts, pistons, gears, hand tools, pipe cutters, concrete
drills, shear blades, cutting tools, punches, embossing dies,
drawing dies, drills, and saws.
|
| Stainless
Steel |
484
lb/ft^3
|
65
ksi
|
260
ksi
|
3.63
$/lb
|
| While
technically contained within the 'alloy steel' category, stainless
steels are given a separate category due to their popularity.
This very corrosion resistant set of alloys contains at least
11 percent Chromium by weight. Typical applications include:
Automotive exhuast, valves, food processing (knives, etc.),
rifle barrels, surgical tools, and springs. |
| Aluminum
& Alloys |
169
lb/ft^3
|
2.5
ksi
|
83
ksi
|
1.814
$/lb
|
| Popular
due to its high strength to density ratio, aluminum is also
corrosion resistant, and easily formed. Its chief drawback is
the relatively low melting temperature (1220º F, 660º
C), which limits its operating environments.
Typical
applications: Sheet metalwork, cooking utensils, buses, trucks,
general structures, furniture, aircraft structures & skins,
crankcases, & aircraft wheels.
|
| Copper
& Alloys |
556
lb/ft^3
|
10
ksi
|
165
ksi
|
4.54
$/lb
|
| These
materials are very easy to cold work (but difficult to work
harden), highly resistant to many different corrosive environments
(air, seawater, and various chemicals), and are very good electrical
conductors.
Typical
applications include costume jewelry, cartridge casings, radiators,
musical instruments, coins, springs, diaphragms, saltwater
piping, battery clamps, and bearings.
|
| Zinc
& Alloys |
444
lb/ft^3
|
10
ksi
|
165
ksi
|
1.814
$/lb
|
| Characterized
by low melting points, non-poluting refining & processing,
and high fluidity, zinc alloys can be cast with thinner walls
and at higher tolerances than most other metals. Zinc also has
good corrosion resistance and sound damping properties.
Typical
applications: flat rolled products, wire drawn products, and
products that are forged, extruded, or cast.
|
| Magnesium
& Alloys |
112
lb/ft^3
|
23
ksi
|
51
ksi
|
3.628
$/lb
|
| Magnesium
has the lowest density of all of the structural metals, so it
often appears in aircraft components. It has a relatively low
melting temperature, (1204º F, 651º C), doesn't corrode
in air, but is very susceptible to corrosion from seawater.
Typical
applications: Missile and aircraft parts up to 400º C,
automotive parts, luggage components.
|
| Titanium
& Alloys |
281
lb/ft^3
|
75
ksi
|
200
ksi
|
13.61
$/lb
|
| A
relatively new engineering material with a lower density, a
high melting point (3035º F, 1668º C), and high tensile
yield strength. The alloys also virtually immune to corrosion
at room temperatures, but become reactive at elevated temperatures
-- resulting in the need for some non-conventional and expensive
refining and casting techniques.
Typical
applications: Airplane structures, space vehicles, chemical
processing equipment, marine components, aircraft engine compressor
blades, and rocket motor cases.
|
| Nickel
& Alloys |
555
lb/ft^3
|
16
ksi
|
26
ksi
|
4.54
$/lb
|
| Nickel
alloys are corrosion resistant in many environments, especially
alkaline rich situations. It is often used for coating metals
less resistant to corrosion, and as an alloying component.
Typical
applications: Pumps, valves, other components in contact with
corrosives, ducts in nuclear power systems, fans, ovens, doctor
blades, dentistry, medical implants, and cryogenic applications.
|
| Refraction
Metals |
636
lb/ft^3
|
75
ksi
|
90
ksi
|
22.7
$/lb
|
| These
metals, such as niobium, molybdenum, tungsten, and tanatlum,
have melting points above 4000º F, and also maintain there
strength and stiffness even at elevated temperatures. Tungsten
is also virtual immune to all forms of corrosion in environments
up to 150º C.
Typical
applications: Extrusion dies, structural parts in space vehicles,
x-ray tubes, light filaments.
|
| Thermoplastics |
68
lb/ft^3
|
1.2
ksi
|
12
ksi
|
1.814
$/lb
|
| Thermoplastics
can repeatedly be changed from a solid state to a maleable state
with the application of heat.They soften when heated, eventually
liquify, and solidfy once more upoon cooling.They are relatively
ductile.
Typical applications:
Countless consumer items. Bowls, buckets, cups, computer/monitor
housings, funnels, spatulas, crash helmets, bottles, appliance
parts, CD cases, snaps, window frames, gutters, etc.
|
| Thermosets |
68
lb/ft^3
|
4
ksi
|
13
ksi
|
1.814
$/lb
|
| The
process of forming a thermoset plastic, called curing,
is irreversible. Epoxies are an example of this material
class; when you mix the liquid ingrediants together, they 'set'
in a solid form. In general, they are harder, stronger, have
better dimensional stability, and are more brittle than thermoplastics.
They are resistant to moisture absorption, are good electrical
insulators, and can withstand higher temperatures before degradation
than a thermoplastic.
Typical applications:
Caulking, adhesives, enapsulation for electronics, transformer
housings, fan blades, brackets, Lucite, Plexiglass, microwaveable
Tupperware, and light switch and electrical outlet covers.
|
| Ceramics |
218
lb/ft^3
|
2
ksi
|
60
ksi
|
0.454
$/lb
|
| The
primary benefit of ceramic materials is there high restance
to thermal shock, and ability to maintain their properties even
when inside a furnace. Due to their extremely brittle nature,
ceramic components should not be expect to carry significant
tensile loads. Very high electrical and wear resistance are
other driving forces behind many ceramic applications.Due to
their chemical inertness, they are often used in medical applications.
Typical applications:
Sinks, bathtubs, bearings, seals, high stiffness / low weight
applications, plates, mugs, dental work, bricks, tiles, furnace
linings, seals, nozzles/molds for molten metal, and engine
/ rocket components. You can even purchase ceramic knives!
|
| PhotoPolymers |
68
lb/ft^3
|
3
ksi
|
8.7
ksi
|
83.9
$/lb
|
| The
photo polymers used in stereolithography
are actually epoxies that are cured using laser light. They
are separated into their own category because they are far more
expensive and more brittle than many of the other thermosets. |
| Wood
(dry) |
28
lb/ft^3
|
1.05
ksi
|
18
ksi
|
0.91
$/lb
|
| Note
that the yield strength for wood can vary drastically depending
on whether or not the load is along the grain or perpendicular
to it! The yield strength given above applies to along the grain.
Typical applications:
Furniture, construction, cutting boards, paneling, tool handles,
etc.
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A very thorough listing of materials and common applications can
be found in Chapter 8 in "Integrated Product and Process Design
and Development," by Edward B. Magrab (1997, CRC Press).
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