Electroplating electric heating tube barrel plating process

Electroplating electric heating tube barrel plating process

The current density varies greatly. Although the cathode current density of barrel plating is relatively large, due to the large difference in current density, most of the current is consumed on the workpiece with high current density, and the average current density is very small. As a result, the cathode current efficiency is low. Thickness is difficult to guarantee.

There is also chemical dissolution during the barrel plating process. When the workpiece is rolled, the current will be intermittent, and the thickening of the coating requires a longer barrel coating time. However, it is still difficult to thicken the coating locally.

Influence of surface condition of electroplated electric heating tube on coverability

The appearance of the base material is one of the main factors that affect the masking ability. The practice shows that when the metal is electro-deposited on different substrate materials, the covering ability of the same plating solution is different and great. For example, when chromic acid solution is used for chrome plating, when metal chrome accumulates on copper, nickel, brass and steel, the coverage of the plating solution can decrease sequentially. This is because when the metal ions are restored and accumulated on different matrix materials, the values of their overpotentials are very different. The drop potential with a smaller overpotential is more positive, and the value of its drop potential can be reached even in the part with a lower current density, so its masking ability is better. The influence of the surface condition of the matrix material on the masking ability is more complicated.

Generally speaking, the masking ability of the same plating solution on the surface of the substrate with high smoothness is better than that on the rough surface. Because of the large surface area, in fact, the current density is low, and it is difficult to reach the separation potential of the metal, but only a lot of hydrogen is separated. In addition, if the surface of the substrate is not properly treated before plating, there are oil films that are not removed, various phase-forming film layers or dirt, etc., which will also hinder the accumulation of the plating layer and reduce the masking ability.

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