E

Elasticity: The property of recovering original shape and dimensions upon removal of a deforming force.

Elastic Limit:  Maximum stress that a material will withstand without permanent deformation. See Yield Strength.

Electrical Precipitator: In air pollution control, the use of electrodes in stack emissions emitting high voltage; particles 0.1 micron and smaller can
be attached and collected at discharge electrode.

Electrochemical Corrosion (Contact Corrosion, Electrolytic Corrosion, Galvanic Corrosion): Localized corrosion from,exposure of an assembly of
dissimilar metals in contact or coupled with one another, i.e., electrochemical action.

Electrode: Compressed graphite or carbon cylinder or rod used to conduct electric current in electric arc furnaces, arc lamps, carbon arc welding, etc.

Electron Microprobe Analyzer:  An instrument for selective analysis of a microscopic area, in which an electron beam bombards the point of interest in Vacuo at a given energy level. Intensity of backscatter is measured to interpret which chemical elements are present and by scanning a large area the
microprobe can analyze chemical composition and indicate the distribution of an element.

Elongation: Amount of permanent extension in the vicinity of the fractures in the tensile test; usually expressed as a percentage of original gage length,
such as 25 percent in 2 in.

Embrittlement:  Loss of ductility. See Acid Embrittlement, Hydrogen Embrittlement.

Endothermic Reaction:  Designating, or pertaining to a reaction which occurs with absorption of heat from the surroundings; as an endothermic substance.

Equilibrium: A dynamic condition of balance between atomic movements, where the resultant is zero and the condition appears to be one of rest rather
than change.

Erosion: Abrasion of metal or other material by liquid or gas, usually accelerated by pressure of solid particles of matter in suspension, and sometimes
by corrosion.

Etchant: A solution for chemical etching the polished surface of a metal specimen to reveal macro- or microstructures when viewed under microscope.

Exothermic:  Formed by or characterized by heat reaction, as in oxidation.

Exothermic Reaction:  Chemical reactions involving the liberation of heat; such as burning of fuel, deoxidizing of iron with aluminum, and a characteristic
of many feeder or riser compounds. See Endothermic Reaction.

Extensometer: An instrument used in the testing of metals to measure small increments of deformation.