MEA109 Part C Flashcards
True or false - Pure iron is unsuitable for use on aircraft.
True
Why is carbon added to pure iron
to increase it strength
What are the 2 components of alloy steel?
Carbon steel and other metal
Low carbon steel
0.1% - 0.3% carbon content
Safety wire
Medium carbon steel
0.3% - 0.5% carbon content
Rod ends, light forgings
High carbon steel
0.50% - 1.05% carbon content
Flat springs, coil springs
What type of steel is used extensively in the manufacture of aircraft bolts & nuts?
nickel steel
Anti-friction ball & roller bearings are made from _______ steel due to its improved hardness & excellent wear resistant properties.
chromium steel
List 2 mechanical properties of chrome nickel steel that makes it suitable for use in manufacture of control cables
high strength
corrosion resistant
What are the 2 other names for chrome nickel steel
stainless steel
CRES - corrosionn resistant stee;
True or false – Fasteners suited for high temperature applications are usually made from inconel.
True
What type of steel is used in the manufacture of spanners?
chrome vanadium
Give 2 examples of aircraft components made from chrome molybdenum steel alloy.
landing gear structure
engine mounts
What type of metal is widely used in the construction of aircraft structures?
aluminium alloy
What is meant by the term “aluminium alloy”
pure aluminium mixed with another metal
1XXX
2XXX
5XXX
7XXX
Pure aluminium
copper
magnesium
zinc
What is the reason that 1XXX series aluminium is not used in the construction of aircraft structures?
Its not strong enough
True of false – 1XXX series has excellent corrosion resistance
True
For aircraft structures, what are the most commonly used aluminium alloys in the 2XXX series?
2017 and 2024 aluminium alloy
ALCLAD is a type of sheet metal that has ______ (material) rolled over an aluminium alloy core to approximately __% thickness on ___ (both or each) side(s).
ALCLAD is a type of sheet metal that has pure aluminium rolled over an aluminium alloy core to approximately 5% thickness on each side(s).
Malleability
able to be pressed, pounded or rolled into various shapes without being damaged
Ductility
ability to be drawn, bent or twisted into various shapes without being damaged
Hardness
ability to resist abrasion, penetration, cutting action or permanent distortion
Brittleness
tendency to break or crack without change in shape
Toughness
able to resist shearing or tearing
Shear
the force of an slicing or cutting an object
compression
the force of crushing an object
torsion
the stress of an object when it is being twisted
Tension
pulling an object apart
What can be achieved by heat treating metals?
To change the mechanical properties so the metal will be more useful
Heat treatment - Hardening
Hardness increases
more brittle
Rapid cooling in quenching medium such as oil, water,
Heat treatment -Annealing
Produces soft, ductile metal
Relieves internal stresses
Very slow cool down in furnace
Heat treatment -Tempering
Relieves internal stresses
Reduces Brittleness
Cooldown in still air (outside furnace)
Heat treatment -Normalisng
Removes internal stresses set up by hear treating, casting, forming, machining
True or false: The letter “T” designation is used to indicate the hardness condition of heat treated aluminium alloys.
True
True of false – Natural ageing process occurs after the soaking step during heat treatment of aluminium alloys.
False
What is meant by the term “natural ageing”?
developing maximum strength
Certain aluminium alloys are solution heat treated then followed by a natural ageing process. These alloys are allowed to naturally age (harden) at room temperature over a period of ____ to develop their full properties after heat treatment
4 days
What heat treatment process would be necessary to avoid cracking of an alloy due to prolonged cold working?
annealing
Brinell Hardness Tester
Forces a hardened spherical ball to indent the metal surface
After test is done, diameter of impression is measured with a calibrated microscope
Rockwell hardness tester
Forces a conical penetrator to indent the material at a specified load
Test hardness numbers are based on difference between depth of penetration at major and minor loads
List 2 problems with the use of cellulose acetate plastics.
Tendency to shrink
Slight yellow tint
List 2 benefits of acrylic plastics over cellulose acetate plastics.
Practically colourless
stiffer than cellulose acetate
What is the effect of further addition of heat on thermosetting plastics once they have been fully cured?
Further addition of heat on thermosetting plastics can cause deformation or structural weakening
What is the definition for a composite material
A material that consists of two or more different meterials
What are the 2 components that make a strong composite part?
fibre, surrounded and held in place by a resin
What is the trade name for aramid?
kevlar
A laminated structure with a core centre is called a _____ structure
A sandwich structure is a laminated structure with a core centre
What document lists the PPE required to worn when working with composite materials & resins?
SDS
Hydraulic system pressure: 1500 psi to 3000psi
CRES - Corrosion resistant steel
Hydraulic system pressure: Pressure up to 1500psi
Aluminium alloy
Hydraulic system pressure: Pressure above 3000psi
Titanium
True or false - The sizes for rigid tubing are measured from the inside diameter of the tubing
False: Measured from outside
Marking decals - Rigid tubing: Blue & yellow background
Hydraulic
Marking decals - Rigid tubing: Grey background
De-icing
Marking decals - Rigid tubing: Red background
Fuel
Marking decals - Rigid tubing: Green background
Breathing Oxygen
What type of rigid tube fitting is used on fluid systems with: High system pressure
Flareless fitting
What type of rigid tube fitting is used on fluid systems with: Very low pressure
Beaded type fitting
Flexible hoses are most suitable for what type of applications?
To connect moving parts with stationary parts in locations which are prone to vibration or require a great amount of flexibility.
Name the 3 items that make up a flexible hose line.
Butyl, Buna - N, Neoprene
What is the purpose of a continuous stripe on the outer cover on some flexible hoses?
The lay line shows that the hose has been installed without twisting. The line has to be straight.
True or false - The sizes for flexible hoses are measured from the outside diameter of the tubing.
False: Measured from inside
True or False -The swaged end fittings on flexible hoses can be reused
False: cannot be reused
What is the colour coding for standard hose fitting made of steel & aluminium alloy?
AN Steel fitting: Black
AN Aluminium fitting: Blue
What is the purpose of fluid line blanks?
to prevent the ingress of any contaminants
