At present, NdFeB electroplating production mainly adopts three major processes or process combinations of galvanizing, nickel/copper/nickel and nickel/copper/chemical nickel. Others such as gold plating, silver plating, tin plating and black nickel plating are generally used in the above process. Additional plating.
1 pre-plating treatment
Due to the special nature of NdFeB material (strong chemical activity, porous surface, etc.), pre-plating treatment is a major difficulty in NdFeB plating technology. After years of practice, it can be solved by the following measures.
That is, the finishing process.
This process can make the surface of the part smooth, smooth and reduce the microscopic area, which facilitates the rapid, uniform and continuous deposition of the coating. The equipment adopts horizontal planetary tumbling machine and vibrating finishing machine (generally called chamfering machine), which adopts planetary motion and vibration principle respectively, which can achieve the finishing effect without damaging the parts. Horizontal planetary hobbing machines are mostly used for finishing of smaller-sized parts, and vibratory finishing machines are often used for finishing of larger-sized parts.
2) Degreasing, pickling and activation.
In addition to the acidity and alkalinity of the oil and pickling solution should not be too strong, so as to avoid corrosion of the parts, and it is necessary to add a substance for the complexation of the antimony in the treatment liquid to prevent the oxidation of the antimony. The acid wash and the activation solution should avoid hydrochloric acid.
3) Ultrasonic treatment.
Ultrasonic cavitation can completely remove the oil, acid and alkali substances in the micropores of NdFeB. In the pretreatment, ultrasonic treatment should be used as much as possible.
In actual operation, the plastic mesh is usually used to carry out manual shaking cleaning after a few parts, and the steps of ultrasonic degreasing, pickling and washing are completed, and then the roller plating is performed.
Although the labor intensity of the workers is slightly larger, the cleaning is thorough and the effect is good.