Test Flashcards
Uniform surface corrosion leads to ____?
PITTING
What kind of process is ANODIZING? Anodizing acts like what?
it is an ELECTROLYTIC process and it acts as an insulator
Uniform surface corrosion can cause ____
causes dulling
Magnesium parts are cleaned with ____
Non metallic tools and chromic acid
Sea planes bilge is the bottom of the fuselage and is inside of the hull and it is protected by
Potassium dichromate
Titanium is inherently ____ …and is it as strong as steel? Is it lighter?
Corrosion resistant and is as strong as steel but 45% lighter than steel
When removing corrosion from magnesium parts use ____
Non metallic stiff bristle brushes - do not use metallic tools
Most aircraft hardware is plated with ___
CADMIUM - should not be used for high temp applications such as 450 degrees as cadmium will diffuse into base metal and will become brittle
Oxidation is known as ____ and occurs when?
DRY CORROSION and occurs when a metal is exposed to a gas containing oxygen
Exfoliation occurs where/how?
Occurs in layered grain structure in extruded materials and looks like flaking and lifting at the surface
Steels corrosion looks like ___
Reddish rust
Anodizing damaged coating can be restored by ____
Partially restore by chemical surface treatment = alodine
Applied by dipping / brushing
Provides an oxide film
Concentration cell corrosion is found where?
Found in overlapping surfaces - fretting
Some metal alloys corrode because they are returning to____
Their natural state
Anode / anodic
Positive charge
Cathodic
Negative charge
Aircraft’s are stored in the desert because
Air is dry less moisture - slows corrosion process
Titanium alloy 6AL4V is a health hazard because …
It is cancer causing - by checking the MSDS
Copper / copper alloys corrosion characteristic
Greenish film (patina)
Welding fluxes are highly ___
CORROSIVE
Galvanizing process involves coating steel with ____
ZINC
Intergranular corrosion is caused by _____
IMPROPER HEAT TREATMENT , located INSIDE the metal
CANT ALWAYS BE DETECTED BY SURFACE INDICATIONS , can be detected by ULTRASOUND or X-RAY
Clean plastic surfaces by
Flush surfaces with COOL CLEAN WATER to dissolve salt deposits and remove loose dirt before using soapy water to prevent scratching
Neutralize NICAD battery with ___
Neutralize LEAD acid battery with ___
BORIC ACID
BAKING SODA / sodium bicarbonate
Corrosion removal by mechanical means you can use ___
ALUMINUM WOOL / ALUMINUM WIRE BRUSH
(do not use steel with aluminum or vice versa)
Smoking rivets is a sign of ____
Fretting corrosion
Control cables are made of ____ and if they show signs on outerwear of corrosion then you must ____
Carbon steel / corrosion resistant steel ; replace the entire cable
Seaplanes and amphibians must be checked more frequently for
Corrosion due to moisture because of their operating environment
ALODINE increases the ____ to ______
THE RESISTANCE TO CORROSION / means slowing down corrosion
ALODINE leaves an ____film on metal for ________
OXIDE FILM on metal for sacrificial corrosion
Galvanic corrosion occurs when
Dissimilar metals make contact with each other and cause corrosion
Lavatories & Galleys are HIGHLY____ areas because
CORROSIVE - Human waste and food are corrosive
Areas must be inspected carefully
In early stages of Intergranular corrosion the corrosion is ___
NOT EASILY VISIBLE
Fretting corrosion results from ___
Tight fitting parts moving relative to another
