Introduction
In the process of electroplating, surface pre-treatment is an important step for the completion of the entire surface treatment process. The pre-treatment of magnetic material electroplating includes degreasing, conversion film, activation and other processes. Due to the various conditions of the workpiece surface and different electroplating processes, the pre-treatment process must be reasonable and reasonable. In this paper, the treatment of magnetic material electroplating before electroplating is discussed in detail.
Degreasing
The oily and unclean surface of the magnetic material must be degreased and cleaned before electroplating. This is to prepare for the formation of a uniform and dense surface of the metal electroplating layer. The common degreasing agent includes alkaline degreasing agent, organic degreasing agent and acid degreasing agent. The degreasing methods include ultrasonic degreasing, alkaline degreasing, ultrasonic degreasing with detergent and chemical degreasing, etc. The degreasing temperature and time of the magnetic material can be determined according to the nature of the degreasing agent. Generally, the optimum degreasing temperature is 40-60℃ and the optimal degreasing time is 10-15min. The degreasing medium used must be clean and filtered in time to ensure that the surface of the material is kept clean.
Conversion film
In order to improve the anti-corrosion performance of the magnetic material and to prepare the surface for the electroplating process, the conversion film should be formed after degreasing and drying. The conversion film is mainly composed of phosphate salts and chromium compounds. The Phosphate film has good adhesion, corrosion resistance and dielectric properties, which can reduce the contact resistance between the workpiece surface and the electroplating layer, and improve the adhesion of the electroplating layer and the workpiece. Special attention should be paid to the chromate treatment. A uniform and dense chromate layer should be formed on the surface of the magnetic material to ensure that the deposition layer and the substrate are firmly combined.
Activation
The purpose of surface activation before electroplating is to activate the workpiece surface and remove oxide film and other substances. Activation can also promote cold welding between metal atoms and catalyze chemical reaction. At the same time, it can increase the hydrophilicity of the workpiece surface and reduce the surface tension, so that the active material ions in the electroplating solution can be better adsorbed on the surface of the substrate, and the electroplating film can be uniform and dense. Common activation processes include chemical activation and anodic activation.
Conclusion
The pre-treatment of magnetic material electroplating is an important process for the success of the entire electroplating process, which should be paid great attention to. The prolinear magnetic material pre-treatment process is degreasing, conversion film and activation, which should be carried out in accordance with the process requirements to ensure that the electroplating process is successful.
