Reasons for discoloration of hardware terminal plating
The plating of hardware terminals has the functions of improving mechanical ability, corrosion resistance, and improving electrical performance. If the plating of hardware terminals changes color, these functions will be unstable and the appearance will be greatly discolored. Let’s analyze the reasons for the discoloration of hardware terminal plating.
1. Related to its structural shape
Compared with strips, hardware terminals have complex structures and large changes in concave and convex parts, which leads to current distribution problems on the surface of parts during electroplating. Therefore, the protruding parts of the parts distribute a lot of current and the plating is very thick: the concave parts distribute very little current and the plating is very thin. Then the plating is thin, the thickness is not enough, and the protective ability is reduced. This is why the concave parts of the hardware terminals change color first and other parts change color later.
2. Related to the performance of the plating solution
The performance of the plating solution is measured by two indicators, one is the plating ability of the plating solution, that is, the plating solution makes the plating thickness evenly distributed on the parts; the other is the depth ability of the plating solution, that is, the plating solution deposits a metal plating in the deep concave parts of the parts. If these two abilities are not good, the plating will be thin, and the plating of the hardware terminals will easily change color.
