الفهرس 
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Abstract
Electrcdeposition involves metal deposition from an electrolyte into a
conductive electrode by application of an electromotive force, The metal ions are
driven through the electrolyte by a combination of electrostatics, diffusion and
convection, and finally cross the solution-electrode interface (the electric double
layer), The metal ion then loses its sheath of solvent molecules (such as water)
or complexing anions (such as cyanide) to become a metal ad atom or adion which
, in tum, moves on the cathode surface by surface diffusion to a site where it is
incorporated into the crystal lattice of the cathcdically formed deposits,
Electrochemical deposition involves reduction of metallic ions from
aqueous, inorganic and fused salt electrolytes. The reduction process,
M’+ (solution) + ne- (metalic lattice) -? M, can be accomplished by
processes in which electrons are supplied by an extemal power supply or by
electroless (autocatalytic) deposition processes in which a reducing agent in the
solution is the electron source (with no extemal power supplied),
Many metals are deposited in a very rough or powdery from[l] when
elecroplating is carried out at the limiting current density, The possibility of
preventing powder formation at the limiting current by means of suitable additive
is of great interest and represent a significant activity in electroplating’f ,
Various organic substances are used as additives in electroplating,
electrowinning and electroforming to produce fine-grained, smooth, bright
deposits, Organic solvents are also employed in the electrcdeposition of metals,
which cannot be electrodeposited directly from aqueous solutions,
The kinetics of the electrodeposition of metals involves mainly two steps.