6.2- Aircraft Materials- Non Ferrrous Flashcards
Why is titanium used widely in the aircraft industry?
High strength, light weight, temp resistance and corrosion resistance.
The weight of titanium is approximately what of steel?
56% but has the same strength.
What temperature is the strength of titanium held too?
800°F or 427°C.
What methods can titanium be worked by?
It can be sheared, drawn, pressed, machined, routed, sawn and nibbled.
What must the cutting dies and shear blades be made of to machine titanium?
Good quality steel and kept very sharp.
Why must a fire extinguisher be kept on hand when working with titanium?
Because the swarf is extremely flammable if a spark gets to it. Its recommended to use a liquid coolant whilst machining.
Titanium is not a good conductor of heat so what happens during machining?
The built up heat doesn’t dissipate.
Name some of the methods developed to machine titanium?
Use low cutting speeds
Maintain high feed rates
Use plenty of cutting fluid
Use sharp tools and replace them at the first sign of wear.
With the presence of oxygen what temperature will titanium ignite?
1065°C (1950°F).
with nitrogen it ignites at 815°C.
Why is pure cast aluminium highly corrosion resistant?
It has a non porous oxide coating that forms on the surface.
Wrought and cast irons are identified by a four digit system, what are the designated by?
The Aluminium Association of America (AA number).
What does the first digit of the AA number show?
Main alloying element.
What does the second digit of the AA number show?
Alloy modification.
0-orginal alloy
1-9- modifications.
What is the melting point of aluminium?
660°C
Aluminium alloys such as 2024 and 7075 are susceptible to corrosion, how are they protected.
With aluminium cladding, sheets of aluminium and 1% zinc.
Thickness is 3-5% of core
If the first digit of the aluminium designation is 2 what alloy is it?
Copper.
If the first digit of the aluminium designation is 3 what alloy is it?
Manganese.
If the first digit of the aluminium designation is 4 what alloy is it?
Silicon.
If the first digit of the aluminium designation is 5 what alloy is it?
Magnesium
6 is magnesium and silicon.
If the first digit of the aluminium designation is 7 what alloy is it?
Zinc.