Cleaning And Corrosion Flashcards
Corrosion treatment requires these basic steps:
Remove
Neutralize
Restore/Protect
3 basic requirements for the formation of corrosion
Electrical potential difference within metal.
Conductive path between areas.
Covered with Electrolyte.
White powder which forms on the surface of aluminum when it corrodes is a…
Chemical Salt
3 steps that can be taken to minimize damage from corrosion:
Minimize electrical potential difference.
Eliminate conductive path with insulating barrier.
Prevent electrolyte contacting metal.
When electrolytic or galvanic corrosion occurs between an aluminum structure and steel bolt, the _____ will be the metal that is corroded.
Aluminum
Another name for dry corrosion is:
Rust/Oxidation
Exfoliation usually develops in _____ metal parts
Extruded
Stress corrosion occurs when a part is under _____ stress in a corrosion environment.
Tensile
Corrosion that forms inside a metal along the grain boundaries is called:
Intergranular corrosion
Intergranular corrosion may often be detected by either of these two types of nondestructive inspections:
X-ray
Ultrasonic
The scum that forms inside the fuel tanks of some jets aircrafts is caused by:
Microbes and bacteria in the fuel.
Type of finish used to protect the inside of a battery box against corrosion is:
Polyurethane enamel
A solution of _____ and water is used to neutralize fumes from a nickel cadmium battery.
Boric acid.
A piano hinge should be lubricated with a _____ lubricant.
Water displacement
Steel cables can be protected from corrosion by spraying them with a _____ lubricant.
Water displacement
Penetrant inspection _____ be used on steel parts to detect a surface crack.
Can
Corrosion may be removed from aluminum surfaces by scrubbing them with…
Nylon scrubber/ Scotch Brite
A chemically deposited oxide film on an aluminum surface is called…
Alodizing
One of the best methods for removing the corrosion products from rusted steel parts is a/an..
Abrasive blasting.
Galvanizing is a method of protecting steel with a coating of?
Zinc
A fully formed anodized film is…
Hard
Before paint will stick to a cadmium plated surface, the surface should be etched with a solution of…
Chromic acid
Highly stressed steel parts should not be cleaned by scrubbing them with a wire brush because of the danger of…
Stress concentrations
Oil and grease may be removed from acrylic plastics and rubber by wiping them with a rag dampened with…
Aliphatic naphtha.
List 9 types of corrosion.
Oxidation, Intergranular, Exfoliation, Stress, Galvanic, High Metallic ion concentration cell, Low Oxygen concentration cell, Fretting, Filiform, Uniform Surface
Six corrosive agents:
Air Water Acidic Alkali Salt Mercury Organic Matter
_____ metals are damaged almost equally by acids or alkalis, but _____ may be damaged more by a strong alkaline solution than by acid.
Ferrous; Aluminum
Filiform corrosion consists of threadlike filaments of corrosion that form on the surface of metals coated with organic substances such as paint. (T/F)
True
What causes intergranular corrosion?
Improper heat treatment
The most fundamental and important rule for corrosion control is to?
Keep it clean.
The use of non-recommended cleaning compounds can result in a condition know as…
Hydrogen Embrittlement.
What causes corrosion in aircraft fuel tanks?
Microbes and Bacteria in the fuel.
Cadmium plating, galvanizing and cladding protect the case metal by a process know as…
Sacrificial corrosion.
An electrolytic process that forms a surface of oxide film is called “chemical treatment or alodining”.
(T/F)
False
What is oxidation?
Dry corrosion or rust
Three types of inspection?
Ultrasonic, X-ray, Visual
7 common locations for corrosion on a plane?
Wheel well, lavatory, battery compartment, inlets for engine, exhaust area, cables, fuel tank.
