01 March 2005
Electrochemical Corrosion - Corrosion which occurs
surface charge. These electrically charged droplets are
when current flows between cathodic and anodic areas
attracted to an electrically grounded workpiece.
on metallic surfaces.
Embrittlement - Severe loss of ductility in a metal alloy
Electrode - A metal or alloy that is in contact with
that results in a sudden, brittle fracture.
passes in either direction between the electrolyte and
Emulsion - One liquid dispersed throughout a second
liquid with which the first liquid will not mix to form a
Electrolysis - Chemical changes, especially
decomposition, in the solution or electrolyte due to the
Enamel - A paint having a high gloss finish.
passage of an electric current. Its relation to corrosion
arises only if the corrosion process alters the make-up
Encapsulant - The general term describing materials
of the electrolyte.
used to encase or fill a void to prevent the entrance of
moisture or fungus. Conformal coatings, fungus-proof
Electrolyte - Any substance which, in solution or when
coatings, and potting compounds are all forms of
fused, disassociates into electrically charged ions that
render the liquid capable of conducting a current. Soluble
acids, bases, and salts, such as sea water, are
Epoxy - A type of paint or resin, adhesive, or plastic
noted for high mechanical strength, good adhesion, and
resistance to solvents, acids, alkalis, and corrosion.
generated from electromagnetic fields which are
Ester/Diester Oils - Oils containing synthetic materials
known as esters or diesters, which are chemically
formed by the reaction of an alcohol and an acid.
designed avionics units, electric motors, and lightning
Examples include jet engine oil (MIL-PRF-23699) and
and other natural effects. This type of radiation can
hydraulic oil (MIL-PRF- 83282). These synthetic oils
interfere with aircraft avionics systems causing electrical
can attack certain plastics and paints.
Erosion Corrosion - Accelerated attack of a metal due
Electromotive Force (EMF) Series - A list of elements
to the relative movement between a fluid and the metal
according to their standard electrode potentials. The
more negative the potential the greater the tendency of
the metal to corrode. A hydrogen gas electrode is the
Etching - The use of a chemical solution or primer to
standard reference and its potential is designated as
prepare a surface for priming or bonding by removing a
zero. All potentials are positive or negative with respect
layer of the base metal.
to the hydrogen electrode. This series does not indicate
rates of corrosion.
Exfoliation - The separation of a material in flakes or
Electronic Countermeasure - An offensive or defensive
tactic using electronic or reflecting devices. It is used to
Expected Maximum Lifetime (EML) - The expected
reduce the military effectiveness of enemy equipment
maximum period of time over which an avionics system,
involving electromagnetic radiation.
subsystem, module or component performs
satisfactorily. This includes acceptable availability,
Electronic Warfare - Warfare directed at the electronic
operation, and support cost (specified number of repair
capabilities of the enemy, to detect and prevent hostile
use of the electromagnetic spectrum. Electronic warfare
Extrusion Grade Sealant - A higher viscosity (8,000 -
16,000 poise) sealant designed for application by
extrusion by a sealant gun. This grade is usually used
Electrostatic Spraying - A system of applying a coating
for forming fillets and sealing vertical surfaces. Usually
in which the coating droplets from an air, air-assisted
designated as a Class B sealant.
airless, or airless spray gun are given an electrical