6.2 Aircraft Materials - Non-Ferrous Flashcards
What are the advantages of titanium in the aircraft industry?
High strength, light weight, temperature resistance and corrosion resistance
What is the weight saving between Titanium and Steel?
56% less (But strength is equal to that of steel)
What temperature is the strength of titanium held up to?
More than 800°F (427°C
Where is titanium useful for in aircraft?
Cooler sections of gas-turbine engines, for cowlings and ba es around engines and for the skin parts of aircraft which may be subjected to elevated temperatures
How corrosive resistant is titanium?
Highly resistant
What substances damage titanium?
Strong reducing acids such as sulphuric or hydrochloric acid as will chlorinated cleaning solutions
At what temperature must titanium be protected from the atmosphere?
1000F (583C) +
How is titanium usually protected from high temperatures?
Heat the metal in Argon or helium gas.
Also inert-gas welding
How much carbon and nitrogen does titanium have in its pure form?
- 1 % Carbon
0. 05% Nitrogen
What tensile strength does pure titanium have?
50,000 - 90,000psi
What alloy increases the tensile strength of titanium the highest?
Manganese (139,000psi)
What is the highest possible tensile strength of titanium via alloying and heat treating?
180,000psi
How much aluminium is commonly used in alloying with Titanium?
3-7%
What must the cutting blades be when cutting titanium?
Very sharp
What safety equipment must be kept nearby when titanium is being cut or ground?
Fire-extinguisher
What 3 things make titanium hard to cut
- Poor conductor of heat
- Chemical reactivity at cutting temperatures
- Low modulus
What 5 machining rules should be put in place when cutting titanium?
- Low cutting speeds
- High Feed rates
- Plenty cutting fluid
- Sharp tools
- Never stop feeding
At what temperature will titanium ignite in the presence of oxygen?
1950°F (1065°C)
At what temperature will titanium ignite with nitrogen?
1500°F (815°C)
How corrosive-resistant is pure 99% aluminium?
Highly corrosive resistant
What is the disadvantage of pure aluminium in aircraft?
Its extremely malleable
What two forms is alloyed aluminium produced in
Cast or Wrought
What grain structure does cast aluminium have?
Very coarse (Brittle)
What is cast aluminium used in?
Aircraft wheels and engine crank cases
What grain structure does wrought aluminium have?
Compressed and tightened as it is forced into shapes of plates, rods, extrusions or skins
What type of alluvium is most aircraft parts constructed of?
Wrought heat- treated aluminium alloys.
How are alloyed aluminium’s identified?
4 digit - Aluminium Association of America (AA-Number)
What does the first digit of the AA number specify?
Identifies the major alloying element
What does the second digit of the AA number specify?
Indicates alloy modi cation
What does the third and fourth digit of the AA number specify?
No special significance
For cast alloys what happens to the fourth digit?
The fourth digit is separated from the rst three digits by a decimal point, and indicates the form, that is to say casting or ingot.
How much lighter is aluminium than steel?
3 times lighter
How much more conductive is one pound of aluminium over one pound of copper?
2 time more electrically conductive
How much more energy is required to remelt aluminium than produce it?
5% more
What types of Aluminium are most susceptible to corrosion?
2024 and 7075
What is cladding?
A thin layer of pure aluminium with 1% zinc on both sides as a means of corrosion protection
How thick is cladding on a material?
3-5% the material thickness
What does the direction of text show in Cladding?
Direction of grain structure
What are the 9 major allying identification elements in order from 1-9
1XXX 99.00% minimum aluminium
*2XXX Copper
3XXX Manganese
4XXX Silicon
5XXX Magnesium
- 6XXX Magnesium and Silicon
- 7XXX Zinc
8XXX Other elements
9XXX Unused series
What is work hardening?
Known as strain hardening or cold working, is the strengthening of a metal by plastic deformation
What is annealing?
Heating the alloys to an elevated temperature, holding or soaking them at this temperature for a length of time depending upon the mass of the metal, and then cooled slowly in still air or switched-o furnace
Where would you find the rate and method of cooling
Detailed in the SRM
When prolonged forming operations are involved, the metal takes on what condition?
Mechanical Hardness. ( which will resist further working)
What type of alloys should not be used in the annealed state for parts or fittings
Aluminium
What is 1100?
Aluminium (pure)
Should Clad parts be heated quickly or slowly when annealing?
Quickly - As longe long exposure to heat tends to cause cladding to diffuse.
In solution heat treating alluvium alloys, what mediums should be used to heat it in?
Molten sodium or potassium nitrate bath or in a hot-air furnace
In solution heat treating alluvium alloys, what is the temperature held at?
Within plus or minus 50C
What is the time frame for quenching solution heat treated ally alloys
10 seconds
What are the common heat treated naturally aged alloys?
2117,2017.2024
How many times can Clad be heat treated?
3 times
What does these basic temper designations stand for?
F - As fabricated
O - Annealed
H - Strain hardened (non-heat-treatable products only)
W - Solution heat-treated
T - Heat-treated to produce stable tempers other than F, O, or H
What do these temper designation for heat treated mean?
T2 - Annealed
T3 - Solution heat-treated and cold worked
T4-Solution heat-treated and naturally aged
T5- Cooled from an elevated temperature shaping process and arti cially aged
T6 - Solution heat-treated and arti cially aged.
What is the weight ratio between aluminium and magnesium?
2/3 the weight of aluminium
Is magnesium magnetic or not?
Not
What gas fire extinguisher should be used on magnesium?
Argon or Helium
When heat soaking magnesium over 18 hours, how thick should it be?
2” +
What should magnesium never be heat soaked in?
Salt bath
What does GLARE stand for?
Glass Reinforced Laminate
What family does GLARE belong to?
Fibre Metal Laminates
What type of cycle is a laminate produced?
Autoclave Curing Cycle
What ways can GLARE be tailored in regards to its make-up?
Number of Layers
Direction of Fibres
How many standard GLARE grades are there?
6
What is the thickness range go Glare laminate aluminium layers?
0.2-0.5mm
What does Glare 4B-4/3-0.4 mean?
- A Glare laminate with bre orientation according to the Glare 4B de nition in the table opposite
- 4 layers of aluminium and 3 bre layers
- An aluminium layer thickness of 0.4 mm
Where are the most important applications of Glare?
fuselage skin structures of the Airbus A380, aircraft cargo bay oors and liners, aircraft cargo explosive resistant containers.
What are the advantageous properties of FML’s?
- Fatigue resistant
- Damage tolerant
- Impact and blast resistant
- Fire resistant
- Thermal isolation
Where is Glare Used?
Leading Edge
Blast Resistant Containers
Cargo Floor
