Corrosion

Front 1

define corrosion

Back 1

the chemical or
electrochemical deterioration of a material

Front 2

why does corrosion occur?

Back 2

because
of the tendency of metals to return to their naturally
occurring state

Front 3

can Corrosion
occur in the absence of water?

Back 3

yes, but only at high
temperatures, such as those found in gas turbine
engines.

Front 4

what is the most common type of corrosion

Back 4

electrochemical corrosion

Front 5

what is The smallest unit of an element

Back 5

an atom

Front 6

__________ is A negatively charged subatomic
particle

Back 6

electron

Front 7

_________ is An atom or group of atoms or molecules
which has acquired a net electric charge by gaining
or losing electrons

Back 7

ION

Front 8

_____ is A liquid (usually water) solution
containing ions

Back 8

ELECTROLYTE

Front 9

the THEORY OF CORROSION is...

Back 9

All metals will corrode
to some extent in a natural environment

Front 10

what Four conditions must
exist before metal corrosion can occur

Back 10

1. metal present
2. the cathode must be present
3. electrolyte must connect the
anode and cathode
4. Electrical contact between the anode and cathode must
exist

Front 11

what are The metals most commonly used in aircraft
construction

Back 11

aluminum, steel, titanium, and
magnesium

Front 12

_____ results from a direct chemical attack on a
metal surface that proceeds uniformly over the entire
exposed surface

Back 12

UNIFORM SURFACE CORROSION

Front 13

______ occurs when different metals are in contact with each
other and an electrolyte

Back 13

GALVANIC CORROSION

Front 14

GALVANIC CORROSION is usually
recognizable by

Back 14

the presence of a buildup of corrosion
deposits at the joint between the metals

Front 15

____ is a form of
extremely localized attack that results in holes in the
metal

Back 15

PITTING CORROSION

Front 16

Pitting is usually first noticeable as...

Back 16

a white or
gray powdery deposit, similar to dust, which blotches
the surface

Front 17

______ is an attack on the grain
boundaries of the metal.

Back 17

INTERGRANULAR CORROSION

Front 18

_____ is where the surface grains of a
metal are lifted up by the force of expanding corrosion
products occurring at the grain boundaries

Back 18

EXFOLIATION CORROSION

Front 19

what is visible evidence of exfoliation corrosion

Back 19

lifting up or swelling

Front 20

_____ is recognized by its characteristic wormlike
trace of corrosion products beneath the coating

Back 20

FILIFORM CORROSION

Front 21

____ is
the increase in the rate of attack on a metal due to the
action of a corrosive fluid against the metal surface

Back 21

Erosion corrosion

Front 22

Erosion corrosion is
characterized by...

Back 22

grooves, gullies, waves, rounded holes
and/or valleys in the metal surface

Front 23

____is the intergranular or transgranular
cracking of a metal caused by the combined effects of
constant tensile stress

Back 23

STRESS CORROSION

Front 24

Stress corrosion appears in the form of...

Back 24

cracks

Front 25

____ is the cracking of metals caused by the combined effects of cyclic stress and corrosion

Back 25

CORROSION FATIGUE

Front 26

___occurs at contact areas between materials under load
subject to repeated vibration

Back 26

FRETTING CORROSION

Front 27

Fretting has the general appearance of....

Back 27

galling, in which chunks of metal are torn from the
surface with corrosion at the torn areas or ragged pits

Front 28

The corrosion
products of _____are white powdery snow-like mounds

Back 28

MAGNESIUM