The failure of yellowing after plating in the barrel nickel plating process in electroplating plant will undoubtedly increase the difficulty of delivery, whether it is the delay of production schedule or the waste of raw materials, it is a loss. So in addition to the yellowing of the water imprint and the yellowing of the pinhole, what other reasons can cause yellowing after plating?
That's the yellowing of the foreign objects
There are two types of foreign objects yellowing:
① The surface of workpiece blank contains foreign objects, usually, it is due to the pre-treatment is not clean or difficult to clean to remove, in the rolling nickel plating process foreign objects can not be dissolved, and interfere with the deposition of the plating layer, resulting in a thin layer or no plating layer.
This yellowing includes yellowing of the foreign substance itself, as well as yellowing of the substrate from unprotected rust overflow.
②Parts containing foreign objects in the plating layer, mostly brightener decomposition, showing yellowish-white color.
Generally speaking, oil, oxide and other soluble impurities on the surface of iron substrate blanks, plating plant through the conventional degreasing, pickling process can be removed, but there are also some can not be thoroughly cleaned up through the traditional pre-treatment process of foreign matter attached to the surface of the parts, resulting in yellowing after plating.
In addition to the importance of the workpiece substrate, we need to choose a suitable nickel plating brightener to get a good quality coating when we are producing nickel plating process. Bigely nickel plating brightener Ni-117 has a uniform thickness, soft white color, good ductility and low stress.
To learn more about the barrel nickel plating process, please contact us.
