Corrosion Control Flashcards
How may filiform corrosion be recognized?
It’s characteristic worm like like trace of corrosion beneath the paint film
Name at least one principle cause of filiform corrosion
Improper or incomplete curing of primer prior to painting or failure to keep acidic surface contaminants washed off
What are the two general conditions that may cause stress corrosion cracking?
Sustained tensile stresses and the corrosive environment
Name at least four procedures commonly used in the corrosion preventative maintenance process
Cleaning, lubrication, treatment, sealing, keep the drain holes clear, drain fuel sumps, use protective covers
Name at least five areas of an aircraft prone to corrosion
Exhaust trail areas, battery, compartment, vent openings, bilge areas, wheel wells, landing gear, wing flap recesses, piano hinges, any areas that can trap water
Why are piano type hinges prime spots for corrosion?
Piano hinges are corrosion prone due to the similar 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?
Kept clean and lubricated
What are the proper tools for removing corrosion from anodize aluminum surfaces?
Aluminum wool, aluminum wire brushes, non-metallic bristle brushes, or scotch Brite
What are some types of light duty cleaning agents?
Soap and water
Why is an aircraft cleaned before inspection?
It enables mechanics to make a more accurate inspection
What are some types of heavy duty cleaning agents?
Solvents and emulsions
What type of agent is preferred for cleaning plastic surfaces such as windshields?
Soap and water
What general precautions should be used when washing an aircraft?
Avoid or protect areas which may be damaged or contaminated: such as bearings, hinges, sealed areas, and Pitot and static ports.
Why should only recommended cleaners be use an aircraft fabric or plastics?
Their use cause less deteriorating effects
Why should aluminum metal polish not be used on anodized aluminum surfaces?
It will remove the oxide coat which is the protective layer
What is the most common type of corrosion?
Surface
What is an acceptable method for removing surface corrosion from titanium?
Stainless steel wool or brush, aluminum oxide paper, Scotch-Brite, abrasive blast with glass beads, hand polish with aluminum polish and soft cotton cloth
Name at least three factors influencing corrosion
Filiform, fretting, intergranular, pitting, galvanic, surface, exfoliation, oxidation, stress
Name at least three factors influencing corrosion
Environmental conditions, type of metal, dissimilar metal, condition of protective coatings, presence of electrolyte and contaminants
What is generally recommended to use when cleaning grease, fuel and oil from aircraft tires?
Soap and water
How may fretting corrosion aluminum be identified?
It has a dark, smoky appearance - it appears around and streaming back from the rivet heads
What is Alodine used for?
Treatment deposits a chemically form oxide on aluminum alloys to improve corrosion resistance and enhance paint bonding qualities
Is it permissible to use steel wool or steel wire brushes on aluminum surfaces?
No, it is not because traces of steel can becoming embedded in the aluminum and cause corrosion
What is one of the most destructive forms of corrosion?
Pitting
