When performing alkaline zinc plating, the following points need to be noted to ensure the quality of the galvanized layer and the durability of the workpiece.
Author: Marisa
When performing alkaline zinc plating, the following points should be noted to ensure the quality of the galvanized layer and the durability of the workpiece:
1. Pre-treatment of workpieces: Pre-treatment of workpieces is a key step, and each process should be strictly controlled to avoid affecting the quality of the galvanized layer. This includes removing oil stains, impurities, etc. on the surface of the workpiece to ensure that the galvanized layer can be evenly and firmly attached to the surface of the workpiece.
2. Control of plating solution and operating parameters: The concentration of zinc ions and sodium hydroxide in the plating solution, as well as the concentration of additives, will directly affect the quality of the galvanized layer of the workpiece. In addition, the current density, temperature, stirring and other operating methods will also affect the quality of the galvanized layer. Therefore, these parameters should be strictly controlled within the process range.
3. Hydrogen evolution reaction: During the plating process, hydrogen will be precipitated on the cathode surface, which may cause adverse effects on the galvanized layer, such as pinholes, pitting, etc. Measures should be taken to reduce these adverse effects.
4. Post-plating treatment: Improper operation of the cleaning, passivation, dehydrogenation and other processes after the workpiece is galvanized will also affect the quality of the galvanized layer. Therefore, these processes should be controlled to ensure the quality of the zinc coating of the workpiece is good .
5. Storage method: After zinc electroplating, the workpiece should be stored in a ventilated and dry place, and avoid being stored in a humid or acid mist place to prevent the workpiece coating from being corroded and affecting the quality of the coating .
6. Use of alkaline zinc plating brightener: Attention should be paid to the amount of alkaline zinc plating brightener added. Excessive use may affect the bonding force of the coating. At the same time, control the residence time of the workpiece in the plating tank to avoid surface passivation .
7. Plating solution maintenance: Pay attention to the concentration of key chemicals in the plating solution, such as the concentration of cuprous cyanide and sodium cyanide, as well as the control of pH and temperature. Proper maintenance of these parameters can ensure the chemical stability of the plating solution, reduce the occurrence of failures, and save production costs .
By paying attention to the above points, the quality and efficiency of alkaline zinc plating can be effectively improved, and the durability and aesthetics of the workpiece can be ensured.