Cleaning and Corrosion Control Flashcards
3 factors that influence corrosion :
1) The environmental conditions
2) The type of metal
3) The presence of a dissimilar metal
4) The condition of protective coatings
5) The presence of contaminants and electrolytes
Name at least three forms of corrosion
1) Surface
2) Dissimilar metal
3) Intergranular
4) Filiform
5) Fretting
Name at least four procedures commonly used in the corrosion preventive maintenance process.
1) Cleaning
2) Lubrication
3) Inspection
4) Treatment
5) Keeping drain holes clear
6) Drain fuel sumps
7) Daily wipe down
8) Sealing
9) Using protective covers
Name at least five areas of an aircraft that are prone to corrosion
1) Exhaust trail areas
2) Battery compartments
3) Vent openings
4) Bilge Areas
5) Wheel wells
6) Landing Gear
7) Wing Flap recesses
8) Piano hinges
9) Any areas that can entrap water
What are the proper tools for removing corrosion from anodized aluminum surfaces?
1) Aluminum wool
2) Aluminum Wire brushes
3) Non-metallic bristle brushes
4) Nylon Scrubber Pads
What general precautions should be used when washing an aircraft?
Avoid or protect areas which may become damaged or contaminated such as:
1) Bearings
2) Hinges
3) Sealed Areas
4) Pitot and static ports
What are some types of light duty cleaning agents?
Soap and synthetic detergents
What are some types of heavy duty cleaning agents?
Solvents and emulsions
What are the two general conditions that may cause stress corrosion cracking?
Sustained tensile stress and a corrosive environment
How may filiform corrosion be recognized?
A blistered paint surface and worm or fern-like patterns under the paint
What type of agent is preferred for cleaning plastic surfaces?
Soap and water or a manufacturer approved cleaner
Why should aluminum metal polish NOT be used on anodized aluminum surfaces?
It will remove the oxide coat
What is generally recommended to clean grease, fuel, or oil from aircraft tires?
Soap and water
Why should only recommended cleaners be used on aircraft fabrics or plastics?
Their use causes less deteriorating effects
Name at least on of the principal causes of filiform corrosion
1) Improper or incomplete curing of wash primer prior to painting
2) Failure to keep acidic surface contaminants washed off
Why is an aircraft cleaned before inspection?
It enables the mechanic to conduct a more accurate inspection
How may fretting corrosion in aluminum be readily identified?
By the appearance of corrosion products residue (frequently originating around and streaming back from rivet heads) having a dark smoky or sooty appearance
Why are piano type hinges prime spots for corrosion?
Piano hinges are corrosion prone due to dissimilar metal contact between the steel pin and aluminum hinge and because of their design which tends to trap contaminants
How are piano type hinges protected from corrosion?
By being kept as clean as possible and properly lubricated
What is Alodine used for?
Alodine treatment deposits a chemically formed oxide on aluminum alloys to improve corrosion resistance and enhance paint bonding qualities.
Is it permissible to use steel wool or steel wire brushes or aluminum surfaces?
No, it is not permissible. The traces of steel can become embedded in the aluminum and cause corrosion.
What is the most common type of corrosion?
Surface
What is an acceptable method for removing surface corrosion from Titanium?
1) Stainless steel wool or brush
2) Aluminum oxide paper
3) Scotch-brite
4) Abrasive blast with glass beads
5) Hand polish with aluminum polish and soft cotton cloth
What form of corrosion is an attack along the grain boundaries of an alloy that is usually caused by improper heat treatment?
Intergranular corrosion
The lifting and flaking of metal surface due to the buildup of corrosion products, as a result of severe Intergranular corrosion, is an indication of what form of corrosion?
Exfoliation
What is another name for corrosion caused by contact of dissimilar metals?
Galvanic corrosion
What form of corrosion can be found in battery compartments?
Direct chemical attack or chemical corrosion
Name at least one type of surface treatment used on aluminum surfaces.
Alodizing and Anodizing
