6.2

Question 1

Why are titanium and it’s alloys used in the aircraft industry?

Answer 1

High strength
Light weight
Temperature resistance
Corrosion resistance

Question 2

How does titanium compare to steel?

Answer 2

Same strength

56% of the weight

Question 3

Where is titanium used in an aircraft?

Answer 3

Cooler sections of the gas turbine engines

Cowlings and baffles

Skin parts that are subjected to high temperatures

Question 4

What does titanium have excellent resistance to?

Answer 4

Oxidising acids

Nitric or chromic acids

Question 5

What will attack titanium?

Answer 5

Strong reducing acids and chlorinated cleaning solutions

Question 6

What is titanium completely inert from?

Answer 6

Stagnant water
Urban atmosphere
Marine atmosphere
Salt water spray
Sea water

Question 7

What type of welding is one of the best for welding titanium?

Answer 7

Inert-gas welding

Question 8

How much carbon and nitrogen does pure titanium have?

Answer 8

Carbon- 0.10%
Nitrogen- 0.05%
(Maximum)

Question 9

What is the tensile strength of pure titanium?

Answer 9

50,000-90,000 psi

Question 10

What is the tensile strength of titanium with manganese added?

Answer 10

139,000 psi

Question 11

How much aluminium is commonly used with titanium?

Answer 11

3-7%

Question 12

What is the highest tensile strength a titanium alloy can be?

Answer 12

180,000 psi

Question 13

What is important for the cutting dies and shear blades when being used on titanium?

Answer 13

Good quality steel

Sharp

Question 14

What is titanium a poor conductor of?

Answer 14

Heat

Question 15

What’s the best way to machine titanium?

Answer 15

Low cutting speed
High feed rates
Use lots of cutting fluid
Use sharp tools and replace upon first signs of wear
Never stop feeding while surfaces are in contact

Question 16

What wil titanium do at 1950^F (1065^C)?

Answer 16

Ignite in the presence of oxygen and burn with an incandescent flame

Question 17

When will titanium ignite with nitrogen?

Answer 17

1500^F (815^C)

Question 18

Is pure cast aluminium corrosion resistant?

Answer 18

Yes

Question 19

Is pure aluminium malleable?

Answer 19

Yes

Question 20

Is pure aluminium heavy?

Answer 20

No

Question 21

What is the grain structure in cast aluminium?

Answer 21

Coarse

Question 22

What is the grain structure in wrought aluminium?

Answer 22

Compressed and tightened

Question 23

How many times lighter is aluminium than steel?

Answer 23

3x

Question 24

Is aluminium corrosion resistant?

Answer 24

Yes

Question 25

Is copper a better electrical conductor than aluminium?

Answer 25

No

Question 26

What is the melting point of aluminium?

Answer 26

660^C

Question 27

What is the density of aluminium?

Answer 27

2.7 Kg/dm^3

Question 28

What is the tensile strength of aluminium?

Answer 28

80 N/mm | Alloyed can be up to 540 N/mm

Question 29

What is the sheeting that covers aluminium to create Alclad?

Answer 29

1% zinc on both sides

Question 30

How thick are the clad layers on alclad?

Answer 30

3-5% of the material thickness of the aluminium

Question 31

Aluminium designation system (wrought alloys)

Answer 31

``` 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 ```

Question 32

Designation system for aluminium (cast alloys)

Answer 32

``` 1XXX 99.00% 2XXX Copper 3XXX Silicon with added copper and/or magnesium 4XXX Silicon 5XXX Magnesium 6XXX Unused series 7XXX Zinc 8XXX Tin 9XXX Other elements ```

Question 33

Explanation of alclad numbering system

Answer 33

A 2 0 24 - T3 A= Alclad-covering 2= copper the main alloying ingredient 0= Modification of alloy 24= alloy designator T3= Solution heat treated, aged, and cold worked

Question 34

What is work hardending also known as?

Answer 34

Strain hardening | Cold working

Question 35

What is work hardening?

Answer 35

The strengthening of a metal by plastic deformation

Question 36

What is annealing?

Answer 36

The heating of alloys, holding or soaking them, the letting them slowly cool in a still air or switched off furnace

Question 37

What is solution heat treatment?

Answer 37

When metals are heated in molten sodium or potassium nitrate or in a hot furnace. The temp. is then held within plus or minus 50^C, the cooled or quenched rapidly

Question 38

What does cold working do?

Answer 38

Causes copper to precipitate at grain boundaries and harden the alloys

Question 39

What is natural age hardening?

Answer 39

Occurs at room temp. | Copper precipitates at the grade boundaries. This hardens the metal to full strength over a period of days

Question 40

What is artificial aging/precipitation hardening?

Answer 40

Where the temp. is raised to 120^C to 190^C

Question 41

How many times can a clad material be heat treated?

Answer 41

3

Question 42

Basic temper designation

Answer 42

``` F= As fabricated O= Annealed H= strain hardened W= solution heat treated T= heat treated to produce stable tempers other than F, O or H ```

Question 43

Is magnesium heavier of lighter than aluminium?

Answer 43

Lighter

Question 44

Why isn’t pure aluminium used?

Answer 44

Highly susceptible to corrosion Difficult to work with Highly flammable

Question 45

What are the advantages of magnesium?

Answer 45

High strength to weight ratio | Non magnetic

Question 46

What does Glare stand for?

Answer 46

Glass Reinforced Laminate

Question 47

What family is Glare part of?

Answer 47

Fibre Metal Laminates (FML)

Question 48

What advantages do FML’s have?

Answer 48

``` High strength Fatigue resistance Damage tolerant Impact and blast resistant Fire resistant Thermal isolation ```

Question 49

Where on the aircraft can Glare be used?

Answer 49

Leading edges Blast resistant containers Cargo floors and liners