When the film layer from a trivalent chromium black zinc passivation process is not dark enough, it usually means that there are certain issues in the process that need to be optimized. Based on years of service cases, Bigely has compiled a few points that can help improve the appearance of the passivated film layer.
1. Passivation solution composition check: The color and gloss of the passivated film layer depend largely on the ratios in the passivation solution. It should be ensured that the concentration of trivalent chromium and the pH of the solution are maintained at the right level. The additives in the solution should also be checked regularly, as these can change over time and with the number of uses.
2. Process parameter tuning: The passivation step needs to be carried out under the conditions specified in the instruction manual to ensure a homogeneous, dark film. Too short a treatment time or too low a temperature may result in an uneven color.
3. Quality of the galvanized layer: The quality of the galvanized zinc layer has a direct impact on the effectiveness of the passivation coating. Before proceeding with the trivalent chromium black zinc passivation process, it is necessary to ensure that the thickness, adhesion and homogeneity of the zinc coating meet the standards. In addition, the microstructure of the plated surface affects the adsorption and reaction of the passivate.
By reviewing and optimizing the above aspects one by one when using the trivalent chromium black zinc passivation process, we can potentially solve the problem of insufficiently dark and bright trivalent chromium black zinc passivation film layers. In the field of electroplating, the quality of the film layer is always the key, and the operational details are often the decisive element for success.
Through continuous improvement of the trivalent chromium black zinc passivation process, the black brightness of the passivated film layer can be significantly improved to achieve the desired decorative and protective effect. If you still can't solve the problem, you can contact Bigely and we will arrange for our technical engineers to communicate with you and provide you with suitable technical solutions.