Nowadays, the proportion of bathroom fittings electroplating in electroplating production is also increasing. Bathroom fittings usually use copper alloys, zinc alloys, and aluminum alloys as base materials, and all have a certain electroplating production process. Various failures are often encountered in the electroplating production process. The author briefly talks about the failure of copper alloy bathroom fittings. 1, glitches Reason There are mechanical particles in the plating solution and they are co-deposited with the plating layer. It comes from the dust brought by the compressed air and the sand particles of the foundry parts are not cleaned up and brought into the plating solution. In addition, the pH value of the plating solution is too high, the formed nickel hydroxide is co-deposited with the nickel layer, and it is mixed in the nickel layer. Processing method (1) When the sand foundry parts are baked in an oven at 350℃, the sand and copper castings will naturally separate. This will reduce the amount of sand carried in. (2) The inlet and outlet of the filter should be modified, that is, the inlet pipe and the outlet pipe are in the same place, and the height difference between the two pipes is 10cm~15cm, so that the sand particles can be completely filtered out. (3) The Roots three-leaf blowing and suction dual-purpose air pump needs to be cleaned frequently, and the filter element should be replaced. It is best to cover the filter element with a cloth for easy cleaning. For the air compressor, a set of purification devices should be installed. (4) Control the pH value of the nickel plating solution within the specified process range to ensure the normal deposition of nickel. 2, variegation Reason (1) Impurities in the plating solution are replaced on the copper plating layer. A certain electroplating factory will leave spots on the workpiece as soon as the workpiece (bathroom fitting) touches the male board pocket. Then, filtering the plating solution with activated carbon is also ineffective. But the author found that the anode bag is very yellow and very yellow, indicating that there are impurities on the anode bag. When the copper-plated workpiece touches, the impurities are adsorbed on the workpiece, leaving mottling, and the metal impurities cannot be removed with activated carbon. (2) The plating solution lacks wetting agent. The usual addition is not enough. Some use carbon cores to filter the plating solution, because the carbon cores are easy to absorb a part of the wetting agent, which reduces the amount of wetting agent in the plating solution. Processing method (1) This phenomenon does not appear only if the plating solution is processed, the anode bag is replaced, the plating solution is filtered, and then electroplating is performed. (2) Add sodium lauryl sulfate to the process range. In addition, currently electroplating manufacturers generally adopt two methods: one is to cut off the power when entering the nickel plating tank, and then turn on the power again after entering the nickel plating tank. Second, take it out after entering the nickel plating tank for a while, wipe it with a clean cloth, and then enter the nickel plating tank. In this way, the plated workpiece will not appear spotted. 3, pitting Reason Currently, the degreasing powder used in the pretreatment of electroplating manufacturers contains sodium silicate. If you do not use hot water to wash, do not take any measures, sodium silicate is difficult to wash. Sodium silicate is activated by hydrochloric acid to generate silicic acid. In the pre-plating copper process, the acid-base neutralization generates new salt, which remains on the coating, forming dense small pits. Therefore, in this kind of unclean condition, this kind of pitting will not appear in the rough nickel plating. Because the rough nickel plating is an acidic bath, there will be no acid-base reaction. Processing method After degreasing, add a hot water washing process or soak HF to eliminate SiF4. 4, water pattern Reason The cracks left when the metal shrinks when the sanitary parts are found to cool. It is difficult to find before plating, and only appears after plating. Processing method For this kind of cracked bathroom fittings, ultrasonic cleaning cannot be used before electroplating, but manual degreasing is required to prevent the cracks from expanding. Copper plating should be thicker, polished after plating, and then plated with copper/nickel/chromium. This way the cracks can be eliminated. In addition, during the casting process, rare earth elements are added to the molten copper water to increase the fluidity of the copper water and reduce the cracks in the bathroom fittings. |
