M6.2 non- Ferrous Flashcards
1
Q
What is a non ferrous metal
A
Metals that have elements other than iron as their base metal.
Non magnetic
2
Q
What are the most common non ferrous metals
A
Aluminium, copper, titanium, magnesium,
3
Q
What is alimunium obtained from
A
An ore called Bauxite
4
Q
What are the characteristics of aluminium
A
White
Lightweight
Corrosion resistant
Very strong
Lacks sufficient strength
Most widely used metal
5
Q
What elements are most commonly used for alloy aluminium metal
A
Copper
Magnesium
Manganese
Zinc
6
Q
When aluminium is alloyed with copper or zinc what happens
A
The alloy is as strong as steel, yet only 1/3 of the weight
Good corrosion resistance too
7
Q
What does ANSI mean
A
American national standards institute
8
Q
What are the two main classes of aluminium
A
Wrought aluminium
Cast aluminium
9
Q
What is wrought aluminium
A
Heated and worked aluminium
Elongsted grain structure
10
Q
What is cast aluminium
A
Moulded and allowed to cool
Brittle grain structure
11
Q
What does the first digit mean
A
Majorly alloying element
12
Q
What does the second digit mean
A
Indicates alloy modification
13
Q
What does the last two digits mean
A
Identify different alloys in the group
14
Q
1xxx?
A
99% pure aluminium
15
Q
2xxx?
A
Copper
16
Q
3xxx?
A
Manganese
17
Q
4xxx?
A
Silicon
18
Q
5xxx?
A
Magnesium
19
Q
6xxx?
A
Magnesium and silicon
20
Q
7xxx?
A
Zinc
21
Q
8xxx?
A
Other elements
22
Q
9xxx?
A
Unused series
23
Q
What are the most common alloys digits used in a situation
A
2024 - copper no mods zinc and magnesium
7075 - zinc no mods zinc magnesium
24
Q
What is clad aluminium
A
A thin layer 3-5 of pure aluminium to a base material by the rolling process at high temps
25
What does cladding ensure
It increases the materials corrosion resistance
26
What can be printed on the material to identify it has been cladded?
ALCAD, CLAD, ALC
27
Does the printed ALCAD run along the grain of the material
Yes
28
What are the miscellaneous non ferrous metals
Magnesium
Titanium
Inconel
Monel
Copper (bronze= copper and tin) (brass= copper and zinc)
29
What are the advantages of magnesium
Low mass to density ration
Good mechanical properties
Lightweight
Strong
Non magnetic
(Lower density than Al and weights 2/3 of it)
30
What are the disadvantages of Magnesium alloys
Susceptible to corrosion
Easily cracks when formed (heat it before to prevent cracking)
Burns readily
Pitting corrosion
31
What is the most common magnesium alloy
AZ31
(3% Al and 1% zinc)
32
What are magnesium alloys commonly used for
Aircraft landing wheels, engine crank cases, valve bodies
33
What do you use to put out a magnesium fire
Sand
34
What are the advantages of titanium alloys
Lightweight
High strength
(Pure titanium 50% lighter than stainless steel)
Soft and ductile
(Density between Al and Iron)
35
What does titanium do to makes it corrosion resistant
from a thin layer of titanium oxide outside the pure metal
36
What are Titanium alloys used for in aviation
Bolts
Fasteners
Firewalls
Hydraulic pipes
Engine compressed blades
37
What are the most commonly used nickel alloys
Monel
Inconel
38
What does Monel contain
68% nickel 29% copper and small amounts of iron and manganese
39
What are the advantages of monel
Can be welded
Good machining characteristics
High strength and toughness
Corrosion resistant at elevated temps
(Some monel containing Al are heat treatable creating strength equivalent to steel)
40
What is monel used for
Gears
Parts of the exhaust
Monel rivets also available
41
What does Inconel contain
80% nickel 14% chromium and small amounts of iron
42
What are the advantages of Inconel
Good strength
Corrosion resistant under extremely high temps
(Similar appearance to stainless steel and used in similar places)
43
What is Inconel used for
Nozzle supports
Fan castings
Blades
(Used in turbine engines)
44
What are 3 copper based alloys
Brass
Bronze
Beryllium
45
What are the advantages of copper alloys
Excellent electrical and theremal conductivity
Malleable
Ductile
46
What are copper alloys most commonly used for
Electrical wiring as it can be
Rolled, drawn, forged, and pressed
47
What is a simple definition of heat treatment
A series of operations involving the heating and cooling of metals in their solid state
48
What is the reason for heat treatments
Makes the metal more useful
Harder, stronger and more resistant to impact
Also more ductile and soft
49
What are the two types of heat treatment for Aluminium alloys
Solution heat treatment
Precipitation heat treatment
50
What is solution heat treatment
Process of heating an aluminium alloy to allow alloying element to mix with base metal
51
What is the process of solution heat treatment
the aluminium alloy is heated in a salt bath (of molten sodium or potassium nitrate)
or in a hot-air furnace from 440 °C – 525 °C (825 °F – 980 °F) (just below its melting point)
duration depends on the thickness and type of aluminium alloy
The temperature is maintained at ±5 °C (±10 °F) long enough for the base metal to be taken into the solid solution with the aluminium.
Once the alloy has been sufficiently heated (soaked),
removed from the furnace and quenched in cold water.
no more than ten seconds elapses between removing an alloy from the furnace and quenching the alloy.
52
What is precipitation heat treatment
Restore strength since material has come out relatively soft after solution heat treatment.
But by precipitation heat treatment become hard and gain strength over time
53
What are the two types of precipitation heat treatment
Natural ageing
Artificial ageing
54
What is natural age hardening
Take quenched alloy out and wait days or weeks for alloy to naturally harden.
(Copper 2024 gains 90% of its strength within first 30 mins and comes fully hard within 5 days)
55
What is artificial age hardening
Process of hardening can be increased of decreased.
Slowed - storing metal at sun zero (-20 degrees c) immediately after removal.
Increased - reheating the metal between 160 - 260 degrees c. And allow to soak.
56
What is the process of annealing
Heated and held at appropriate temperatures (mass dependent)
Cooled very slowly in still air or a furnace.
(Can be done several times)
57
What does annealing do to a material
Softens and decreases internal stress
58
What can go wrong when annealing clad alloys
If heating is not properly controlled when heating clad alloys it causes the core material to mix with the cladding material. Reducing corrosion resistance
59
Can you use annealed parts no aircraft’s
No
60
What does T3 mean (temper designator)
Solution heat treated and cold worked
61
What does T4 mean
Solution heat treated and naturally aged
62
What does T6 mean
Solution heat treated and artificially aged
63
How many times can you re heat cladded materials
3, otherwise there could be a diffusion of base material into the cladding, decreasing corrosion resistance
64
Why would you reheat materials more than once
To relieve stress
65
What does strain hardening do
alters the grain structure and hardens the alloy by rolling, drawing, or pressing.
66
What is strain hardening also known as
cold working or work hardening.
67
At what temperature range is a metal strain hardened
at a temperature below its critical range
68
What is the different between strain hardening a heat treatable alloy compared to a non heat treatable alloy
Heat treatable alloys have their strength increased by rolling after they have been solution heat treated.
non-heat treatable alloys are hardened in the manufacturing process when they are rolled to their desired dimensions.
69
Does pure aluminium benefit from heat treatment
No, pure aluminium has no alloying materials therefore does benefit.
70
What is alloy 3003
3003 is almost identical to pure aluminium, except for a small amount of manganese
therefore does not benefit from being heat treated.
71
What is alloy 5052 and why is it important when talking about cold working.
Alloy 5052 most important of the non-heat treatable aluminium alloys.
contains 2.5% magnesium and small amount of chromium.
It is used for welded parts such as fuel or oil tanks and for rigid fluid lines.
Its strength is increased by cold working.
72
What series are non heat treatable aluminium alloys
1xxx, 3xxx, and 5xxx series
Their properties can be altered by cold working or rolling
73
How can an alloys hardness or temper be indicated
by a letter that is separated from the alloy designation.
A number following the letter to show when basic temper of the alloy is present.
(Sorry this one is confusing :)))))))
74
What does F mean
F: As fabricated
75
What does O mean
O: Annealed, re-crystallised (wrought materials only)
76
What does H mean
H: Strain hardened
77
What does H1 mean
H1: Strain hardened only
78
What does H2 mean
H2: Strain hardened and partially annealed
79
What does H3 mean
H3: Strain hardened and stabilised
