The principle of electroplating
Electroplating is a technology that uses electrolysis to process surface parts. During electroplating, the part in the electroplating solution is negatively charged, and the metal ions are deposited on the surface of the part under the action of the DC power supply to form a uniform and dense metal layer.
1. Necessary conditions for electroplating: external DC power supply, electroplating solution, electroplating workpiece, and anodizing bath.
2. Use of electrolysis: changing the appearance and physical and chemical functions of parts to achieve multiple technical functions such as decoration, corrosion resistance, and wear resistance.
3. Crystallization of the electrolysis process: the metal ions or complexions in the electrolysis process accumulate the metal coating during the recovery of the cathode, which is called electrolytic crystal.
Electrolytic crystal is a kind of electrochemical reaction process, and metal ions can be recovered by the determination of the cathode point. Only when the cathode potential violates the equilibrium condition and a certain over-potential occurs, can the metal crystals accumulate on the cathode.
4. Metal electroplating is a messy process, it usually has several successive or all interface response steps:
A. The metal ions in the solution reach the vicinity of the cathode surface through electrical relocation, convection, dispersion, and other methods.
B. Before recovery, chemical transformation occurs near or on the outside of the cathode.
C. Metal ions obtain electrons from the cathode surface and then regenerate into metal atoms.
D. Metal atoms scatter along the surface to the growth point to enter the quality growth or meet with other particles to form nuclei and grow into crystals.