Module 6.2

Question 1

What does the term non-ferrous mean?

Answer 1

A non ferrous material is one that has an element other iron as it’s base material.

Question 2

What ore is aluminium obtained from?

Answer 2

Bauxite

Question 3

What two elements when alloyed with aluminium improve strength? And are they lighter or heavier than steel?

Answer 3

Copper and zinc.

Lighter by a 1/3

Question 4

What do each digit in the aluminium alloy index refer to?

Answer 4

1st Main alloying element
2nd Modifications
3rd and 4th Alloy designators

Question 5

What does the term modification mean with respect to aluminium alloys?

Answer 5

Heat treatment of the alloy

Question 6

What two alloying elements of aluminium are prone to corrosion?

Answer 6

Copper and zinc

Question 7

How is corrosion overcome in 2024 and 7075 aluminium alloys?

Answer 7

Cladding with pure aluminium.

Question 8

What thickness is ALClad.

Answer 8

3-5%

Question 9

How can Cladded material be indentified?

Answer 9

Printed with Clad, Al-Clad, A or ALC

Question 10

What is the most common magnesium alloy used in aircraft?

Answer 10

AZ31

Question 11

Why is AZ31 used in aircraft?

Answer 11

Good mechanical properties and low mass density. 2/3 the mass of aluminium.

Question 12

In AZ31 what does each character mean?

Answer 12

A - refers to Aluminium
Z - refers to Zinc
3 - refers to 3% Aluminium content
1 - refers to 1% Zinc content

Question 13

How much lighter is pure Titanium than CRES?

Answer 13

50% lighter

Question 14

What properties do alpha alloys of titanium have?

Answer 14

Medium strength and good elevated temperature strength.

Can be welded and forged.

Question 15

What properties do alpha-beta alloys of titanium have?

Answer 15

Medium strength once annealed and much higher strength when heat treated.

Question 16

What properties do beta alloys of titanium have?

Answer 16

Medium strength and has excellent characteristics for forming.

Question 17

What are the two nickel alloys?

Answer 17

Monel and Inconel

Question 18

What are the breakdowns of both nickel alloys?

Answer 18

Monel - 68% nickel and 29% copper
Inconel - 80% nickel and 14% chromium

Question 19

What to property do copper alloys have?

Answer 19

Good electrical and heat conductors

Question 20

What are 3 common copper alloys?

Answer 20

Brass, Beryllium and Bronze

Question 21

What two types of heat treatment are used on aluminium alloys?

Answer 21

Solution and precipitation

Question 22

What are the 3 ways to solution heat treat?

Answer 22

Molten sodium bath
Molten potassium nitrate bath
Hot air furnace

Question 23

In solution heat treatment what is the range in temperature?

Answer 23

440 - 525 degrees centigrade

Question 24

What is the maximum amount of time allowed between soaking and quenching?

Answer 24

10 seconds

Question 25

What 2 alloys of aluminium cannot be heat treated?

Answer 25

Copper, 2017 and 2024

Question 26

What is natural ageing?

Answer 26

Alloying an alloy to cool at room temperature.

Question 27

How much strength do aluminium alloys gain in the first 30 minutes?

Answer 27

90%

Question 28

How long does it take to fully harden an aluminium alloy?

Answer 28

4 - 5 days

Question 29

How can age hardening be slowed?

Answer 29

Holding the material at -20C in a freezer.

Question 30

Why may magnesium alloys be used other alloys?

Answer 30

-2/3 as much as aluminium -non magnetic

Question 31

What series of alloys are non-heat treatable?

Answer 31

1, 3 and 5

Question 32

How do you strain harden a material?

Answer 32

Mechanically working a material when it is below its upper critical limit.

Question 33

What type of heat treatment uses natural ageing?

Answer 33

Precipitation.

Question 34

How can age hardening be sped up?

Answer 34

By heating the metal to between 160 - 260C

Question 35

How do you anneal aluminium alloys?

Answer 35

Heating to 415C and soaking. Cooled to 260C at a rate of 25C. After 260C cooling rate is not important.

Question 36

What are the 4 aluminium alloy temper designations? (Name)

Answer 36

T, T3, T4 and T6

Question 37

What does T refer to in aluminium alloys?

Answer 37

The alloy has been solution heat treated.

Question 38

What does T3 refer to in aluminium alloys?

Answer 38

Solution heat treated followed by strain hardening.

Question 39

What does T4 refer to in aluminium alloys?

Answer 39

The alloy underwent solution heat treatment followed by natural ageing.

Question 40

What does T6 refer to in aluminium alloys?

Answer 40

The alloy underwent solution heat treatment followed by artificial ageing.

Question 41

What does reheat treatment do?

Answer 41

Relives internal stresses, improves mechanical properties and allows cold working of the material.

Question 42

What does the F in hardness designators?

Answer 42

F - fabricated

Question 43

What does O represent in the hardness designators?

Answer 43

O - annealed

Question 44

What does the H refer to in the hardness designator series?

Answer 44

H - strain hardened

Question 45

What does the first digit after the H represent in the hardness designators?

Answer 45

H1, H2, H3 - refers to if the material has been further treated or not

Question 46

What does the second digit after the H represent in the hardness designators?

Answer 46

2, 4, 6, 8, 9 - represent the hardness

Question 47

Does wrought aluminium have a coarse or fine grain structure?

Answer 47

Fine structure