|
vacuum
deposition
Condensation of thin metal coatings on the cool
surface of work in vacuum.
valence
A positive number that characterizes the combining
power of an element for other elements, as measured by the number of bonds
to other atoms that one atom of the given element forms upon chemical
combination: hydrogen is assigned valence 1, and the valence is the number
of hydrogen atoms, or their equivalent, with which an atom of the given
element combines.
vapor
deposition
See chemical
vapor deposition, physical vapor deposition and sputtering.
|
|
vapor
plating
Deposition of a metal or compound on a heated surface
by reduction or decomposition of a volatile compound at a temperature below
the melting points of the deposit and the base material. The reduction is
usually accomplished by a gaseous reducing agent such as hydrogen. The
decomposition process may involve thermal dissociation or reaction with the
base material. Occasionally used to designate deposition on cold surfaces
by vacuum evaporation. See also vacuum deposition.
voids
A term generally applied to paints to describe holidays,
holes, and skips in a film. Also used to describe shrinkage in
castings and weld.
|