Principle of the electroplating process
Principle of electroplating
1. 1 Electroplating Definition
Electroplating is an electrodeposition process in which a metal is attached to the surface of an object by means of an electric current passed through an electrode with the aim of changing the characteristics or dimensions of the surface.
1. 2 Purpose of electroplating
The purpose of electroplating is to apply a metallic coating (deposit) to a substrate in order to change the surface properties or dimensions of the substrate. For example, to give the surface of the metal glossy and beautiful, goods rust, prevent wear; improve electrical conductivity, lubricity, strength, heat resistance, weather resistance; heat treatment of anti-carburization, nitriding; size or wear of the parts repair.
1. 3 various gold plating methods
Electroplating method (electroplating) Electroless plating method (electrolessplating)
Hot dip plating Melt spraying (sprayplating)
Plastic plating Impregnation plating
Infiltration plating cathodesupptering
Vacuum plating
Alloy plating
composite plating partial plating (selectiveplating)
through-hole plating penplating
Electroforming
1.4 Basic knowledge of electroplating
Most of the plating is carried out in liquid (solution) and mostly in aqueous solution (aqueoussolution). About 30 kinds of metals can be plated by aqueous solution, for example: Cu, Ni, Cr, Zn, Cd, Pb, Au, Ag, Pt, Co, Mn, Sb, Bi, Hg, Ga, In. Hg, Gallium Ga, Indium In, Thallium, As, Se, Te, Pd, Mn, Re, Rh, Os, Ir, Nb, W, etc.
Some metals must be plated from non-aqueous solutions, e.g. Lithium, Sodium, Potassium, Beryllium, Magnesium, Calcium, Strontium, Barium, Aluminium, La, Ti, Zr, Ge, Mo, etc. Metals that can be plated by aqueous and non-aqueous solutions are: copper, silver, zinc, cadmium, antimony, bismuth, manganese, cobalt, nickel, etc.
The following are also included: Solution properties Substance reactions Chemical formulae Electrochemistry Interfaces Physical chemistry Material properties
1.4.1 Solutions
A substance that is dissolved is called a solute and a substance that dissolves a solute is called a solvent. A solution in which the solvent is water is called an aqueous solution. The amount of solute dissolved in a solution is called concentration. In a given amount of solvent, the maximum amount of solute that can be dissolved is called solubility. A solution that reaches the solubility value is called a saturated solution, while the opposite is an unsaturated solution.
solution.) The concentration of a solution is known and easily understood as weight percentage and commonly used as molarconcentration in production and operational management.
1.4.2 Reaction of matter
In the electroplating process there are physical and chemical changes, e.g. grinding, drying, etc. are physical reactions and in the electrolytic process there are chemical reactions, we must fully understand the interrelationships and effects of the various physical and chemical reactions in the process.
