12. Loose branched plating. This occurs when the plating solution is dirty, the concentration of the main metal ions is high, the complexing agents are low, additives are low, the cathode and anode are too close, and the current density is too high. In the current zone, loose branched plating tends to form. The loose plating looks like foam plastic, with uneven, branched structures that can be wiped off the surface with a finger.

13. Double-layer plating. Double-layer plating typically occurs when the operating temperature of the plating solution is high, and when a workpiece is removed from the plating tank and re-entered for further plating. During this process, if the workpiece is removed for too long, the plating solution on the surface evaporates and forms a salt crust. When the workpiece is re-plated, the salt crust has not yet dissolved, and the plating forms on top of it, creating a double-layer plating effect, resembling a biscuit with a layer of salt crust between the two plating layers.

14. Black plating. The main cause of black plating is the high content of metallic and organic impurities in the plating solution, particularly in the low current density areas, where the plating tends to be darker. Inadequate additives can also lead to black plating in the middle of a large plating area. Low temperatures and low ion activity can also cause gray-black plating when current density is high.

15. Passivation peeling. Pre-plating activation includes two chemical processes: one is the oxidation process, and the other is the dissolution of the oxide. If the oxidation process is insufficient or the oxide is not dissolved in time, the surface may still contain oxide residues, causing the plating layer to peel off or become rough.

16. Displacement peeling. This typically happens when a workpiece is made from two different materials.

17. Oil contamination peeling. If oil is not fully removed during pre-plating treatment, areas with oil contamination will not form a plating layer, or if plating occurs, it will be fake plating without adhesion. The plating layer will peel off easily like a rash, and it will come off with just a touch.

18. Dark circular spots on the plating. When the plating solution has many impurities or insufficient additives, dark gray circular spots form in the center of the heat sink, resembling a patch. This is because the central area, which has a low current density, accumulates impurities. If additives are insufficient, the plating solution's depth ability decreases.

19. Uneven gloss and thickness of the plating layer. This occurs when additives are added and not fully dispersed, leading to inconsistent plating characteristics.

20. Chemical fiber contamination in the plating solution. This results in visible chemical fibers embedded in the plating layer. The problem can be resolved by using an iron to weld and cut the PP cloth used for the anode bag.

21. Fungal contamination in the plating solution. This is common in nickel plating tanks where the pH of 4-5 is ideal for fungal growth. Fungal bodies may be embedded in the plating layer. In such cases, disinfection measures must be taken. To prevent fungal contamination, it is essential to implement proper startup procedures for the production line.

22. Moss contamination of water quality. When the workpieces are rinsed in water containing moss, the moss adheres to the workpieces. After drying, it sticks firmly, affecting the product quality. Moss contamination is more likely in the spring, and preventive measures should be taken. If moss contaminates the plating tank, it can be embedded in the plating layer.

23. High porosity of the plating layer. The primary cause is a dirty plating solution with high metallic and organic impurities.

24. Regular differences in plating thickness on the same rack. This is caused by inaccurate projection of the anode and cathode shapes (the relative position of the anode and cathode is unsuitable), leading to uneven distribution of the electric field.

25. Tin lumps on the plating surface. This happens when anode mud contaminates the plating solution. PP bags that are damaged cause anode dissolution to introduce both ion and atomic forms into the plating solution. When atomic groups contact the workpiece, they are embedded in the plating layer, forming tin lumps.

28. Black bodies with discolored appearance. This occurs when the frame stays in the alkaline liquid of the pre-plating treatment or neutralizing tank for too long, causing the black body to be eroded by the alkali. The black body contains epoxy, leveling agents, curing agents, anti-aging agents, white fillers, and black pigments. When the black body is eroded by the alkali, the fillers are exposed.

For more information, please visit: Guangdong Jianzheng Electromechanical Plating Equipment Technology Co., Ltd.