Aircraft Corrosion Flashcards
What is true about magnesium and magnesium alloys?
It is very lightweight
It is very susceptible to corrosion
It can burn with intense heat
Anodizing produces a protective coating of aluminum oxide which:
Is quite hard
How can intergranular corrosion be detected?
May exist without visible surface evidence
Which of the following types of electroplating will give good protection to steel and is most commonly used on aircraft hardware?
Cadmium
What is the best reason why an aircraft should have a good polish on its finish?
It denies corrosion a place to start
What is another name for Smoking Rivets?
Fretting corrosion
Which is true about mild corrosion?
Is less than .001 inch in depth
May use a non-chlorine abrasive cleaner for removal
May use scotchbrite pads for removal
What is Galvanizing ?
A coating of zinc that makes an oxide coating when penetrated which protects the metal
What is an anode?
Metal that gives up electrons
Which of the listed conditions may be one of the requirements for corrosion to occur?
An anodic and cathodic metal present
The presence of an electrolyte
Electrical contact between an anodic area and a cathodic area
What is the primary cause of intergranular corrosion?
Improper heat treatment
How are magnesium engine parts cleaned?
Wash with a commercial solvent or grit blast
Which solvent is recommended for wiping down clean surfaces just before painting?
Aliphatic naphtha
Which of the following are acceptable to use when utilizing chemical cleaning and/or painting removal agents on aircraft?
- Synthetic fiber wiping cloths when using a flammable agent
- Cotton fiber wiping cloths when using a flammable agent
- Atomizing spray equipment
2 and 3
Caustic cleaning products used on aluminum structures may produce what negative effect?
Corrosion
Which of the following are the desired effects of using Alodine on aluminum alloy?
- A slightly rough surface
- Relieved surface stresses
- A smooth painting surface
- Increased corrosion resistance
1 and 4
Corrosion, which occurs with most metals, is the result of:
A tendency for them to return to their natural state
What do you call a nonelectrolytic chemical treatment for aluminum alloys to increase corrosion resistance and paint-bonding qualities?
Alodizing
Which of the following are acceptable to use when cleaning anodized surfaces?
- Steel wool
- Brass wire brush
- Aluminum wool
- Stainless steel wire brush
- Fiber bristle brush
3, 5
Of the following, when and/or where is galvanic corrosion most likely to occur?
At the interface of a steel fastener and aluminum alloy inspection plate in the presence of an electrolyte
Of the following, when and/or where is galvanic corrosion most likely to occur?
At the interface of a steel fastener and aluminum alloy inspection plate in the presence of an electrolyte
(1) In the corrosion process, it is the cathodic area or dissimilar cathodic material that corrodes.
(2) In the galvanic or Electro-Chemical Series of metals, the most anodic metals are those that will give up electrons most readily.
Regarding the above statements:
Only number two is true
One way of obtaining increased resistance to stress corrosion cracking is by:
Creating compressive stresses on the metal surface
Which solvent is recommended for cleaning acrylics and rubber?
Aliphatic naphtha
