When we use the trivalent chrome color zinc passivation solution to produce, sometimes the coating film will have poor adhesion and easy peeling. How to solve this?
Bigolly Technology made an analysis based on the field experience and the characteristics of the product's trivalent chrome color zinc passivation solution BZ-208, summarized 5 methods that can prevent the delamination of the passivation film of the workpiece:
1. The galvanizing solution should be analyzed and adjusted in time.Whether it is an acid zinc plating solution or an alkaline zinc plating solution, it is necessary to ensure that the concentration of the plating solution components is within the process range.
2. Control the current density during the galvanizing process.Although high current can improve the deposition rate, it is easy to cause too much organic impurities in the coating, resulting in high brittleness of the coating.The passivation film thus obtained is prone to fogging, dullness and poor adhesion.
3. Regularly aging the passivation solution.After the passivation solution works for a period of time, the passivation effect will decrease due to the influence of zinc ions and iron ions.Regularly aging the passivation solution and replenishing the original solution can improve the passivation effect of the passivation solution and prevent the coating of the workpiece from peeling off.
4. The workpiece should be washed clean.When the workpiece comes out of the galvanizing tank, the organic film adsorbed on the surface should be cleaned as much as possible to ensure the good adhesion of the passivation film.
5. Baking curing is very important.After the workpiece is passivated by color zinc, the process of baking and curing is very important.It can pack the passivation film with strong adhesion and improve the corrosion resistance of the coating.
Therefore, we need to remember these 5 points when using the trivalent chromium color zinc passivation solution, which can effectively prevent the passivation film from peeling off the workpiece and reduce the occurrence of failures.