The reasons for discoloration of hardware part plating

The hardware part plating has the functions of improving mechanical capacity, corrosion resistance, and improving electrical performance. If the plating of product is discolored, these functions will be unstable and the appearance will be greatly lost. So what makes it discolored? Below we analyze the reasons for the discoloration of metal product plating.

1. It is related to its structural shape: compared with the strip, the hardware terminal has a complicated structure and a large change in the unevenness, which leads to a problem of current distribution on the surface of the part during the electroplating process. Therefore, the protruding portion of the part is distributed with a large amount of current, and the plating layer is thick; the current is distributed in the recessed portion, and the plating layer is thin. Then the coating is thin, the thickness is not enough, and the protection ability is reduced. This is the reason that the recess of the product is discolored first and the other parts are discolored.

2, Related to the performance of the plating solution: the performance of the plating solution is measured by two indicators, one is the plating capacity of the plating solution, that is, the plating solution makes the coating thickness evenly distributed on the part; the other is the depth capability of the plating solution, ie The plating solution deposits a metal coating on the deep recess of the part. These two capabilities are not good, the coating is thin, and the metal product plating is easy to change color.

3. It is related to the speed of movement: the crystallization process of metal ions on the hardware terminals must involve a time factor. The same machine, plating solution, process, if the parts are plated for a long time, the coating is thick, the time is short, and the plating is thin. This plating time actually refers to the problem of electroplating speed of parts. If the walking time is short, the plating layer will be thin, and the hardware product plating coating will be easily discolored, and vice versa.

Fortunately, at DG Fortuna Metals, we have been working with several seasoned and reliable plating suppliers who can gurantee the plating requirements of stamping parts and CNC machining parts.