How Much Do You Know About Bright Nickel-Plated
Many of our products have bright nickel plating applied, do you know what it is? Bright nickel plating is very versatile, it can omit the heavy polishing process and obtain a bright coating.
Bright nickel plating is realized by adding brightener to ordinary nickel plating solution, and nickel plating brightener is divided into primary brightener and secondary brightener, also called softener and main brightener.
Classification of Nickel Plating Brighteners
The primary brightener can make the nickel layer have good ductility, fine crystallization and uniform luster, but it cannot make the coating produce a mirror-bright nickel layer. To make the coating brighter, a secondary brightener must be added.
When the plating solution contains a secondary brightener, the effect of the primary brightener is more obvious, the bright plating range is increased, and a mirror bright coating can be obtained in a wide range of current density.
The addition and control of brighteners are very important. Since the content of brightener in the plating solution is relatively low and the control range is relatively small, the quality problems of bright nickel plating are not only affected by the content of solution components and foreign metal impurities, but also related to the brightener and its decomposition products.
Process flow of bright nickel plating
Pre-inspection - organic degreasing - drying - chemical degreasing - washing - corrosion - washing - hanging - weak corrosion - washing - dark nickel plating - washing - weak corrosion - washing - bright nickel plating - washing - drying.
Common faults and troubleshooting methods of bright nickel plating
✔️The coating is not bright enough
When the surface of the coating is not bright enough, we first check whether the current is too small, increase the current after adjusting the pH value and temperature, and see whether the brightness of the coating increases. If the brightness of the coating has not changed, it is initially determined that the secondary brightness is missing.
To do the Hull cell test, we first add a small amount of secondary brightener, gradually increase from less to more, and compare the added amount with the cathode sample of known content until the test cathode plate is consistent with the standard content of the cathode plate until. While observing the test cathode plate, we also need to see whether the stress of the coating increases.
✔️The coating is foggy and flowery
When adding brightener to the plating tank, be sure to stir evenly. If the stirring is not uniform, the coating will not only bloom, but sometimes white fog, but also cause the coating to brittle.
If the coating is evenly stirred and there are spots, it may be that the primary brightener has been added too much, and the excess brightener can be removed by electrolysis. Another possibility is that it has been placed for too long after plating without cleaning.
✔️The coating has an orange peel phenomenon
Orange peel phenomenon, sometimes the incoming material itself is not uniform, this phenomenon is generally seen in dark nickel. If the dark nickel coating is uniform, this phenomenon occurs because the content of primary brightener is too high or the pH of the solution is too high.
Measure the pH first, and adjust the pH back first if abnormal. If the orange peel phenomenon does not improve after adjusting the pH, then treat the solution brightener by electrolysis or activated carbon, and then adjust the content of the brightener through the Hull cell test.