notes

1. AIRCRAFT MATERIALS
Basic requirements
• High strength and stiffness
• Low density= high specific properties e.g.
strength/density, yield strength/density, E/density
• High corrosion resistance
• Fatigue resistance and damage tolerance
• Good technology properties (formability,
machinability, weldability)
• Special aerospace standards and specifications

2. Basic aircraft materials for airframe
structures
• Aluminium alloys
• Magnesium alloys
• Titanium alloys
• Composite materials

6. Designation of aluminum alloys
according to EN
EN (European Norm)
• The format includes the prefix EN, followed by
AC or AW, depending on if the alloy is wrought
(AW) or cast (AC).

7. Wrought Alloys

8. What is Mn
• Maganese is a chemical element with symbol
Mn.
• It has the atomic number 25
Role of Mn in steel?
Manganese removes oxygen and sulpher
when iron ore(an iron and oxygen compound)
is converted into iron.

9. Aluminium – Alloys
Aluminium – Al
• melting point 660 °C
• density 2.7 g/cm³
• very good electrical and heat conductivity
• very good corrosion resistance
• low mechanical properties

10. Aircraft Grade Aluminum
• Aluminum plays a vital role in the construction
of aircraft.
• Its high resistance to corrosion and good weight
to strength to cost ratio makes it the perfect
material for aircraft construction.
• But the one property that makes aluminum the
ideal metal for aircraft construction is its
resistance to UV damage.

11. Some of the aircraft-grade aluminum
alloys include:
• 2024-T3
• 6061-T6
• 5052 – H32
• 3003-H14
• 7075-T6

12. 2024-T3
• Grade 2024-T3 is the most common high-strength aluminum
alloy.
• It is often considered aircraft quality.
• It has excellent fatigue resistance even though its corrosion
resistance is lower than that of 6061.
• This aluminum alloy sheet is commonly used to make the
fuselage, wing skins, aircraft structure, and cowls( In aircraft,
the cowl (or cowling) is a housing or removable covering for
the engine) of most airplanes.
• It's also ideal for repairs and restoration because it has a

13. 6061-T6
• This alloy is best known for its high corrosion
resistance and finish.
• It is easy to weld and has almost the same
strength as mild steel.
• Grade 6061-T6 is often used to make landing
mats for aircraft, truck bodies, and frames as
well as structural components.
• It can be fabricated using the most common
techniques which is an excellent property.

14. 5052 – H32
• 5052-H32 is a non-heat treatable (aluminum alloys
that are combined with alloying elements before any
heat treatment. Initially, the strength of these alloys is
achieved by the addition of other elements..
• It is not structural but has high fatigue strength
compared to other alloys.
• It also possesses excellent corrosion resistance,
particularly in marine applications.
• Its excellent workability makes this aluminum sheet
ideal for the construction of fuel tanks.

15. 3003-H14
• This aluminum sheet has great workability and is
one of the most widely used aluminum alloys.
• It is made from a blend of pure aluminum and
manganese.
• This sheet is also non-heat treatable but can be
deep drawn, welded, spun, or brazed.
• It's perfect for making cowls in aircraft and baffle
plating(A baffle plate is a plate designed to
restrain or regulate the flow of fluid)

16. 7075-T6
• The primary role of this aluminum alloy is to
strengthen aluminum aircraft structures.
• The alloy is made from a careful mixture of
copper, magnesium, and zinc to give it extra
strength.
• However, because of copper, it is difficult but not
impossible to weld.