The peeling of the coating on Nickel Plated Parts is a common problem and may be caused by a variety of factors.
First, improper pre-plating treatment is an important reason. If there are contaminants such as oil, rust, and oxide layer on the surface of the parts, which are not completely removed before nickel plating, the bonding between the coating and the substrate will deteriorate, making it easy to peel off. For example, incomplete degreasing will leave grease residues, hindering the deposition and bonding of nickel ions.
Improper control of the composition and process parameters of the plating solution can also cause problems. If the parameters such as the main salt concentration, additive content, pH value, temperature and current density in the plating solution deviate from the appropriate range, it will affect the quality and structure of the coating. For example, too low a main salt concentration may cause the coating to crystallize coarsely and the bonding strength to decrease; too high a current density may cause the coating to burn, thereby reducing the bonding strength between the coating and the substrate.
The material and surface roughness of the part substrate also affect the peeling of the coating. Parts with uneven substrate material, internal defects or stress concentration are prone to poor bonding during the nickel plating process. A surface that is too rough will make the coating uneven at the microscopic level, easily forming weak points and causing the coating to peel off; while a surface that is too smooth may reduce the adhesion of the coating.
Improper operation during nickel plating is also a factor. For example, uneven stirring of parts in the plating solution during electroplating will lead to uneven coating thickness and excessive local stress, which will cause peeling. In addition, plating time that is too long or too short may affect the quality and bonding strength of the coating.
During use, environmental factors may also cause coating peeling. For example, if parts are exposed to harsh environments such as high temperature, high humidity, and strong corrosion for a long time, the coating may oxidize, corrode or expand, and then separate from the substrate.
In addition, improper treatment after nickel plating cannot be ignored. For example, if timely and appropriate passivation treatment is not performed after plating, or if it is hit and scratched during transportation and storage, it may damage the coating and cause peeling.
In short, there are many factors that lead to the peeling of the nickel plated parts, including pre-plating treatment, plating solution composition and process parameters, substrate material and surface state, operation process, use environment and post-plating treatment. In order to avoid the peeling of the plating, strict quality control and management are required throughout the nickel plating process, from parts preparation, plating solution control, operation specifications to post-plating treatment.
