A customer has reported that in the newly configured plating solution using zincate zinc plating additives, the main salt components and operating parameters of the plating solution are within the process range. However, the galvanized layer of the workpiece is prone to defects such as darkening and embrittlement. What is the reason for this?
Based on on-site experience and analysis of the characteristics of the product zincate zinc plating additive BZ-515, Bigley Technology has summarized three factors that affect the performance and quality of the zinc plating layer:
1. The purity of the water quality and raw materials used. When we use groundwater to prepare the plating solution, regardless of which additive is used, the appearance of the workpiece coating will be very poor, and even using a low current electrolytic plating solution cannot achieve good results. Only by adding a large amount of coordination masking agent at once can the plating effect be better. Therefore, the water quality of the plating solution is very important, and it is recommended to use pure water for preparation, rather than groundwater. In addition, zincate plating solution is very sensitive to metal impurities, and industrial grade raw materials may contain harmful impurities, which can seriously affect the performance of the plating solution and the coating after use. Therefore, Bigley suggests that customers should choose analytically pure raw materials.
2. Method for removing impurities from plating solution. For the newly configured plating solution, it is invalid to use Sodium sulfide to remove heavy metal impurities, and zinc ions will also precipitate. Part of Zinc sulfide is colloidal suspension, which cannot be filtered out, and the plating solution will be milky white. When adding zinc powder for replacement, due to the high viscosity of the plating solution, some suspended solids are difficult to filter out. However, if the deposited zinc powder is not filtered in a timely manner, it will dissolve and impurities will enter the plating solution again. So, when the effect of adding coordination masking agent to the newly prepared plating solution is still not good, it indicates that there are many organic impurities in the plating solution. 1-3g/L activated carbon can be used for purification treatment and filtration removal.
3. The quality of the additives used. Some additives on the market produce a large amount of organic decomposition products during the production process, especially when the feeding ratio and synthesis conditions are not appropriate, the organic impurities generated will cause a decrease in the brightness and deep plating ability of the coating. In addition, additives that deteriorate due to prolonged storage can result in poor performance and quality of the coating even if a large amount of coordination agents are added to mask metal impurities during production. Therefore, we should conduct tests before preparing the plating to confirm the good performance of the additives used, and cannot blindly add additives directly to the plating.
Therefore, we should pay attention to the above three points when using zincate zinc plating additives to prepare the plating solution, which can effectively ensure the performance and quality of the plating solution and the galvanized layer of the workpiece, and reduce the occurrence of faults. If you are interested in zincate zinc plating additives, please contact Bigley customer service to obtain free samples and detailed technical information!
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