A: From a long-term production proved, electroplating production quality accidents that occur, most are not caused by the plating process itself. Mostly due to pre-plated metal products caused by improper handling. The other is the smoothness of the coating, adhesion strength, corrosion resistance and other performance quality, and the quality of the pros and cons before plating process is closely related. Metal products in the plating surface state before its cleanliness is the ability to obtain high-quality coating the important part. In the rough metal surfaces, it is difficult to obtain a smooth shiny coating, but also more porous coating, to reduce the corrosion performance. Metal surface if there was a grease, the coating can not be obtained correctly.
12 In the cyanide bath, what is the definition of free cyanide?
A: In the cyanide bath, unbound in the excess cyanide complex salt called free cyanide. For example, in the free cyanide cyanide copper plating solution is the formation of [Cu (CN) 3] = excess cyanide complex ions outside.
13 In the cyanide copper, the anode passivation, poor solubility, free cyanide content Why will rise?
A: In the cyanide copper plating, the anodic dissolution poor, although some oxidation of cyanide consumed at the anode, but the cathode due to copper cyanide complex ion discharge, resulting in a more free cyanide, leaving the bath elevated levels of free cyanide.
14 copper plating anode material have any effect on the quality of the coating?
A: In the copper plating process, the use of copper anode, easy to produce copper, causing rough coating, and brightener consumption of fast, so should be used to contain small amounts of phosphorus (0.1 to 0.3%) of the copper anode, can significantly reduce copper. However, with a high phosphorus copper anode, the anodic dissolution performance will deteriorate, resulting in decreased copper content in the bath.
15 nickel plating solution, the anode area is reduced, the anode current density is increased, when the pH value is increased or decreased?
A: The pH of the solution decreases. This is because the anode to reduce the current density increases, but does not dissolve the anode passivation occurs, the anode passivation, the precipitation of oxygen, the solution H <SUP> + </ SUP> increase,
tungsten copper alloy increasing acidity, pH decreased.
16 nickel plating solution, to promote anodic dissolution, what should be added? Adding large amounts of boric acid can do?
A: To promote the dissolution of nickel anode, should be added to the amount of chloride ions. Boric acid does not promote the role of anodic dissolution of nickel.
17 bright nickel plating solution should pay attention to those harmful impurities interference?
A: bright nickel plating to note:
(1) industrial raw materials impure. Such as nickel sulfate containing copper, zinc and nitrate, the anode nickel plate containing iron and other impurities;
(2) contamination of the production process. If not thoroughly cleaned, or hanging from the product into the copper, chromium. Organic additive decomposition products. These are bright nickel-plated harmful impurities, should be taken to exclude.
