The performance of the plating solution has a direct impact on the quality of the plated layer. The performance of the plating solution includes the main salt, conductive salt (supporting electrolyte), complexing agent and some additives. The concentration of the main salt affects the roughness of the plated layer and the deposition rate.
Author: Anna
The performance of the plating solution has a direct impact on the quality of the plated layer. The performance of the plating solution includes the main salt, conductive salt (supporting electrolyte), complexing agent and some additives. The concentration of the main salt affects the roughness of the plated layer and the deposition rate. The role of conductive salt is to increase the conductivity of the plating solution and regulate the pH of the solution, thus affecting the physicochemical and anodic properties of the plating layer. The addition of complexing agent can improve the cathodic reduction polarization, which is conducive to obtaining detailed, compact and good quality plating layer, but the cost is higher. The additives can adsorb on the electrode surface, change the structure of the double electric layer at the electrode-solution interface, and affect the properties of the electrodeposited layer, such as hardness, internal stress and brittleness. In addition, the nature of the solvent also has an impact on the quality of the plated layer, which needs to have a high dielectric constant to ionize the dissolved electrolyte completely or mostly into ions.
Plating process conditions are also important factors affecting the quality of the plated layer. The size of the current density directly affects the crystalline fineness and hardness of the plated layer. When the current density is large, the number of nuclei formed increases, and the plating layer crystallization is fine and compact, but the current density is too large, there will be dendritic crystals and pinholes. An increase in electrolyte temperature favors the formation of larger grains, but too high a temperature results in the formation of coarse crystals and more porous layers. Stirring the electrolyte helps to reduce the concentration polarization, obtaining a dense coating and reducing hydrogen embrittlement. In addition, the use of electrolyte pH, inrush current and commutation current also has a certain effect on the quality of the plated layer.
In summary, the quality of plating layer can be effectively improved by optimizing the performance of the electrolyte and strictly controlling the plating process conditions.