Formation Flashcards
(17 cards)
Corrosion Definition
Natural occurrence that attacks metal by chemical or electrochemical action and converts it back to a metallic compound
Corrosion is a natural phenomenon which
attacks metal and converts metals into metallic compounds such as oxides
hydroxides
sulfates
What are substances that cause corrosion called
corrosive agents
What agents are included
acids and alkalis
salts
H20
What produces the most prominent corrosive agents in aviation
H20 or H20 Vapor containing salt
Appearance of corrosion - aluminum alloys and magnesium
appears as surface pitting and etching white and sometimes grey powdery deposits
copper and copper alloys
greenish film
steel
reddish rust
What are the 2 classifications of corrosion
chemical (disolve) and electro chemical
how is chemical corrosion caused
by direct exposure of bare surface from caustic liquid or gaseous agent
What is electro chemical corrosion
corrosive results of 2 metals in contact with each other
2 dissimilar metals in an electrolyte
causes corrosion- one of the metals will corrode- gives up electrons
When a metal gives up an electron its known as a
anodic metal
metals that do not give up electrons easily
cathodic
A ___ is the ____ which allows electrons to travel when 2 dissimilar metals are in contact This is classified as
electrolyte . conductor
Galvanic action
Galvanic action
metals are brought into contact with acid or alkalis (electrolytes)
Electro Chemical corrosion takes place when
2 dissimilar metals are in contact with each other in the presence of an electrolyte
such as hydrochloric acid or plain H20
