The pretreatment process of Nickel Plated Parts is crucial to ensure the quality of nickel plating. Good pretreatment can improve the bonding strength between the plating and the substrate, reduce plating defects, and extend the service life of parts.
The first is degreasing. The purpose of this step is to remove impurities such as oil, grease, etc. on the surface of parts. Usually, organic solvent cleaning, alkali cleaning or emulsifier cleaning are used. Organic solvent cleaning can quickly dissolve grease, but there may be environmental and safety issues. Alkali cleaning uses alkaline solution to saponify grease to remove grease, which has good effect and low cost. Emulsifier cleaning disperses grease in the cleaning liquid through emulsification, and the cleaning effect is relatively mild. After degreasing, rinse the parts thoroughly with clean water to ensure that there is no residual cleaning agent on the surface.
Next is pickling. Pickling is mainly to remove oxides such as scale and rust on the surface of parts. Commonly used pickling solutions include hydrochloric acid, sulfuric acid, etc. During the pickling process, the concentration, temperature and time of the acid should be controlled to avoid excessive pickling and excessive corrosion of the substrate. After pickling, it is also necessary to rinse with clean water to prevent the residual acid from having an adverse effect on the subsequent process.
Then comes the activation treatment. The purpose of activation is to form an active layer on the surface of the parts and improve the bonding strength of the nickel plating layer. Activation can be carried out by dilute acid immersion, electrochemical activation and other methods. Dilute acid immersion can slightly corrode the surface of the parts, making them rougher, increasing the surface area, and facilitating the adhesion of the nickel plating layer. Electrochemical activation is to apply current in a specific electrolyte to cause an electrochemical reaction on the surface of the parts to form an active layer.
In addition, for some parts with special requirements, polishing may be required. Polishing can remove fine scratches and unevenness on the surface of the parts, making the surface smoother and improving the gloss and uniformity of the plating. Polishing can be carried out by mechanical polishing, chemical polishing or electrochemical polishing.
In short, the pre-treatment process of Nickel Plated Parts includes steps such as degreasing, pickling, activation and possible polishing. Each step requires strict control of process parameters to ensure the treatment effect. Only after good pre-treatment can a high-quality nickel plating layer be obtained to improve the performance and service life of the parts.
