Some customers consulted that in the production process of using zinc-nickel alloy color passivation agent, sometimes the workpiece coating can not produce color after passivation. What caused this?
Bigley Technology has made an analysis based on field experience and the characteristics of the product zinc-nickel alloy color passivator BZ-234, which are mainly due to the following three reasons:
1. The nickel content of the zinc-nickel alloy coating on the workpiece is too high or too low. Generally, in zinc-nickel alloy coatings, when the nickel content is greater than 16%, it will lead to poor passivation of the coating in the high current area, resulting in a black or yellow-blue passivation film; and when the nickel content is less than 12%, it will cause medium The plating layer in the low current area turns black or brown. Therefore, we should strictly control the nickel content of the coating in the range of 12-15% during the production process.
2. The pH and temperature of the passivation solution are too high or too low. During the production process, the pH value and temperature of the plating solution are too high or too low, which will affect the nickel co-deposition rate, thereby changing the passivation performance of the alloy coating. If using BZ-234 color passivation solution, the temperature should not exceed 30℃, and the pH value should be controlled within the range of 1.8~2.2.
3. The problem of passivation liquid itself. Some passivators have problems with their own technical formulations, which lead to problems such as narrow operation range, unstable passivation color, unevenness, etc., which are not easy to operate, and it is difficult to control a uniform color passivation film during the production process. Therefore, we should choose a passivation agent with guaranteed quality, such as BZ-234 color passivation agent BZ-234, which has good chemical stability and a wide operating range. The workpiece can easily obtain a uniform color passivation film and has good corrosion resistance. .
Therefore, we need to pay attention to the above three points when the workpiece coating is not colored during the production process of using the zinc-nickel alloy color passivator, so as to solve the problem as soon as possible and reduce the loss. If you are interested in zinc-nickel alloy color passivators, please contact Bigley customer service to get free samples and detailed technical information!