Materials and performance.

Materials and
Aluminium and Titanium
• Aluminium and
titanium are two
very important
metals used in
aircraft industry.
Properties of aluminium
• Pure aluminium is a silverywhite metal with many
desirable characteristics. It is
light, nontoxic (as the metal),
nonmagnetic and nonsparking.
• It is decorative. It is easily
formed, machined, and cast.
Alloys with small amounts of
copper, magnesium, silicon,
manganese, and other
elements have very useful
• Strength depends on
purity. 99.996 per cent
pure aluminium has a
tensile strength of about
49 Megapascals (MPa),
rising to 700 MPa
following alloying and
suitable heat treatment.
• Although not found free in
nature, Aluminium is an
abundant element in the
earth's crust.
• A key property is low
density. Aluminium is only
one-third the weight of
• Aluminium and most of its
alloys are highly resistant
to most forms of
corrosion. The metal's
natural coating of
aluminium oxide provides
a highly effective barrier
to the ravages of air,
temperature, moisture
and chemical attack.
• Aluminium is a superb
conductor of electricity. This
property allied with other
intrinsic qualities has ensured
the replacement of copper by
aluminium in many situations.
• Aluminium is non-magnetic
and non-combustible,
properties invaluable in
advanced industries such as
electronics or in offshore
• Aluminium is non-toxic
and impervious, qualities
that have established its
use in the food and
packaging industries
since the earliest times.
• Other valuable properties
include high reflectivity,
heat barrier properties
and heat conduction. The
metal is malleable and
easily worked by the
common manufacturing
and shaping processes.
• Physical Properties Density /
Specific Gravity ( at
20 °C)2.70Melting Point
(°C)660Specific heat at 100
°C, cal.g-1K-1 (Jkg-1K1)0.2241 (938)Latent heat of
fusion, cal.g-1 (
(397.0)Electrical conductivity
at 20°C
(% of international annealed
conductivity (cal.sec-1cm1K-1)0.5Thermal emmisivity
at 100°F (%)3.0Reflectivity
for light, tungsten filament
• These properties can be very
significantly altered with the
addition of small amounts of
alloying materials. Aluminium
reacts with oxygen to form a
microscopic (0.000000635cm)
protective film of oxide, which
prevents corrosion.
• Aluminium in massive form is
non-flammable. Finely divided
particles will burn. Carbon
monoxide or dioxide,
aluminum oxide and water will
be emitted. This is a useful
property for making rocket fuel.
Uses of aluminium
1) Low density and strength
make it ideal for
construction of aircraft,
lightweight vehicles, and
An alloy of aluminium called
duralumin is often used
instead of pure aluminium
because of its improved
2) Easy shaping and corrosion
resistance make it a good
for drink cans and roofing
3) Corrosion resistance and low
density leads to its use
for greenhouses and window
• 4) Good conduction of heat
leads to its use
for boilers, cookers and
• 5) Good conduction of
electricity leads to its use
for overhead power cables
hung from pylons
(low density gives it an
advantage over copper).
• 6) High reflectivity makes it
ideal for
mirrors, reflectors and heat
resistant clothing for fire
Properties of titanium
• Titanium is lightweight,
strong, corrosion resistant
and abundant in nature.
Titanium and its alloys
possess tensile strengths
from 30,000 PSI to 200,000
PSI, which are equivalent to
those strengths found in
most of alloy steels. The
density of titanium is only 56
percent that of steel, and its
corrosion resistance
compares well with that of
platinum. Of all the elements
in the earth’s crust, titanium
is the ninth most plentiful.
• Titanium has a high
melting point of 3135°F
(1725°C). This melting
point is approximately
400°F (220°C) above the
melting point of steel
and approximately
2000°F (1100°C) above
that of aluminium.
Uses of titanium
• Titanium is important
as an alloying agent
with aluminium,
manganese, iron, and
other metals. Alloys of
titanium are principally
used for aircraft and
missiles where
lightweight strength
and ability to withstand
extremes of
temperature are
• Titanium has potential
use in desalination
plants for converting
sea water into fresh
water. The metal has
excellent resistance to
sea water and is used
for propeller shafts,
rigging, and other parts
of ships exposed to salt
• In this slide show I now know that
titanium is a better material than
aluminium and that it does not corrode
in sea water. I also know that many
things are made from aluminium. They
have this type of metal because it gives
off a good finish and is lightweight.