Aircraft Materials, Processes and Hardware PDF
Aircraft Materials, Processes and Hardware PDF
Aircraft Materials, Processes and Hardware PDF
Hardness
Strength
Density
Malleability
Ductility
Elasticity
Toughness
PROPERTIES OF METALS
Brittleness
Fusibility
Conductivity
Thermal Expansion
AIRCRAFT METALS
Ferrous Metals
Non-Ferrous Metals
FERROUS AIRCRAFT
METALS
Chromium steel
- high in hardness, strength, and
corrosion resistant properties
- adaptable for heat-treated forgings
which require greater toughness and
strength
- used for such articles as the balls and
rollers of antifriction bearings
TYPES, CHARACTERISTICS, AND
USES OF ALLOYED STEELS
Chrome-Vanadium Steels
- approximately 18 percent vanadium
and about 1 percent chromium
When heat treated, they have strength,
toughness, and resistance to wear and
fatigue
SAE 6150 is used for making springs
TYPES, CHARACTERISTICS, AND
USES OF ALLOYED STEELS
Inconel
- Tensile strength : 100,000 psi
(annealed), 125,000 psi (hard rolled)
- Highly resistant to salt water
- Able to withstand temperatures as high
as 1,600 oF
NONFERROUS AIRCRAFT
METALS
The term ―nonferrous‖ refers to all metals
which have elements other than iron as their
base or principal constituent.
This group includes such metals as:
- Aluminum
- Titanium
- Copper
- Magnesium
- Monel
- Babbit
NONFERROUS AIRCRAFT
METALS
K = tan (θ / 2)
Jo-Bolts
Jo-bolt is a trade name for an internally
threaded three-piece rivet. The Jo-bolt
consists of three parts — a threaded
steel alloy bolt, a threaded steel nut,
and an expandable stainless steel
sleeve.
AIRCRAFT BOLTS
Lockbolts
Lockbolts are used to attach two materials
permanently.
They are lightweight and are equal in
strength to standard bolts.
The lockbolt is generally used in wing splice
fittings, landing gear fittings, fuel cell fittings,
longerons, beams, skin splice plates, and
other major structural attachments.
AIRCRAFT BOLTS
(Lockbolts continued…)
Like the rivet, the lockbolt requires a
pneumatic hammer or ―pull gun‖ for
installation; when installed, it is rigidly
and permanently locked in place.
AIRCRAFT NUTS
SELF-LOCKING NUTS
These nuts are acceptable for use on
certificated aircraft subject to the
aircraft manufacturer’s recommended
practice sheets or specifications.
Two types of self-locking nuts are
currently in use, the all-metal type, and
the fiber or nylon type.
AIRCRAFT NUTS
CHECKNUT (AN316)
The checknut is used as a locking
device for plain nuts, screws, threaded
rod ends, and other devices.
AIRCRAFT NUTS
WINGNUTS (AN350)
The wingnut is used where the desired
torque is obtained by use of the fingers
or handtools.
Wingnuts are normally drilled to allow
safetying with safety wire.
AIRCRAFT NUTS
SHEET SPRING NUTS (AN365)
Sheet spring nuts are commonly called speed nuts.
They are used with standard and sheet metal self-
tapping screws in nonstructural applications.
They are used to support line and conduit clamps,
access doors, etc.
Their use should be limited to applications where
they were originally used in assembly of the aircraft.
AIRCRAFT NUTS
Part numbers designate the type of nut. The
common types and their respective part numbers
are: Plain, AN315 and AN335; castle AN310;
plain check, AN316; light hex, AN340 and
AN345; and castellated shear, AN320. The
patented self-locking types are assigned part
numbers ranging from MS20363 through
MS20367.
The Boots, the Flexloc, the fiber locknut, the elastic
stop nut, and the self-locking nutbelong to this
group. Part number AN350 is assigned to the wing
nut.
AIRCRAFT NUTS
Lockwashers
Both the AN935 and AN936, are used with
machine screws or bolts where the self-
locking or castellated-type nut is not
appropriate.
The spring action of the washer (AN935)
provides enough friction to prevent
loosening of the nut from vibration.
AIRCRAFT WASHERS
Lockwashers should never be used under
the following conditions:
With fasteners to primary or secondary
structures
With fasteners on any part of the aircraft
where failure might result in damage or
danger to the aircraft or personnel
Where failure would permit the opening of a
joint to the airflow
AIRCRAFT WASHERS
Where the screw is subject to frequent
removal
Where the washers are exposed to the
airflow
Where the washers are subject to corrosive
conditions
Where the washer is against soft material
without a plain washer underneath to
prevent gouging the surface
AIRCRAFT WASHERS
Special Washers
The ball socket and seat washers,
AC950 and AC955, are special
washers used where a bolt is installed
at an angle to a surface, or where
perfect alignment with a surface is
required. These washers are used
together.
CONTROL CABLES
Cable Fittings
Cables may be equipped with several
different types of fittings such as terminals,
thimbles, bushings, and shackles.
Terminal fittings are generally of the swaged
type. They are available in the threaded
end, fork end, eye end, single shank ball
end, and double shank ball end.
CONTROL CABLES
The ball end terminals are
used for attaching cables to
quadrants and special
connections where space is
limited. Figure 5-68
illustrates the various types
of terminal fittings.
The thimble, bushing, and
shackle fittings may be
used in place of some
types of terminal fittings
when facilities and supplies
are limited and immediate
replacement of the cable is
necessary.
CONTROL CABLES
Turnbuckles
A turnbuckle assembly is a mechanical screw
device consisting of two threaded terminals and a
threaded barrel. Figure 5-69 illustrates a typical
turnbuckle assembly.
Turnbuckles are fitted in the cable assembly for the
purpose of making minor adjustments in cable
length and for adjusting cable tension. One of the
terminals has right-hand threads and the other has
left-hand threads. The barrel has matching right and
left-hand internal threads. The end of the barrel with
the left-hand threads can usually be identified by a
groove or knurl around that end of the barrel.
CONTROL CABLES
CONTROL CABLES
When installing a turnbuckle in a control
system, it is necessary to screw both of the
terminals an equal number of turns into the
barrel.
It is also essential that all turnbuckle
terminals be screwed into the barrel until not
more than three threads are exposed on
either side of the turnbuckle barrel.
After a turnbuckle is properly adjusted, it
must be safetied.
WELDING & BRAZING
Common defects to
avoid when fitting
and welding aircraft
certification cluster.
WELDING & BRAZING
Spot Welding
Two copper electrodes are held in the jaws
of the spot welding machine, and the
material to be welded is clamped between
them.
Pressure is applied to hold the electrodes
tightly together, and electrical current flows
through the electrodes and the material.
WELDING & BRAZING
Figure 4-31. In spot welding, heat is produced by electrical resistance between copper electrodes.
Pressure is simultaneously applied to electrode tips to force metal together to complete fusing
process. Spot-weld-nugget size is directly related to tip size.
WELDING & BRAZING
TYPES OF WELDING
Gas Welding
A fuel gas such as acetylene or
hydrogen is mixed inside a welding
torch with oxygen to produce a flame
with a temperature of around 6,300 °F
(3,482 °C).
WELDING & BRAZING
This flame is used to melt the materials to be
welded.
A filler rod is melted into the puddle of molten metal
to reinforce the weld.
When highly-reactive metals such as aluminum are
gas welded, they must be covered with flux to
exclude oxygen from the molten metal and keep
oxides from forming which would decrease the
strength of the weld. (An illustration of a carburizing
flame, a neutral flame, and an oxidizing flame is
shown in figure 4-28.)
WELDING & BRAZING
Figure 4-29. Set TIG welder to DC Figure 4-30. Set TIG to AC current
current, straight polarity for welding mild for welding aluminum and
steel, stainless steel and titanium. magnesium.
WELDING & BRAZING
WELDING & BRAZING
BRAZING
Brazing refers to a group of metal-
joining processes in which the bonding
material is a nonferrous metal or alloy
with a melting point higher than 425 °C
(800 °F), but lower than that of the
metals being joined.
WELDING & BRAZING