Nickel Plating Bath Formula
Nickel plating is an electrochemical plating process for depositing a layer of nickel alloy on a different metal substrate. The nickel plating process produces an electrically conductive coating of excellent corrosion resistance and a low friction surface. It also improves wear resistance, enhances the brightness and increases wearability of products.
The nickel plating process consists of preparing, activating and plating stages. All of these steps have to be performed properly in order to achieve desired results.
AS THE FIRST STEP, PREPARATION
The preparation stage is the most important step prior to electroplating and should not be overlooked. It includes cleaning the surface, etching, and passivating. Proper preparation requires proper cleaning and etching that removes contaminants, oils, and other surface defects. Proper passivation is important to remove any free iron that could contaminate the final nickel plated layer.
The type of cleaner required depends on the substrate material. An alkaline cleaner is typically used for steel, aluminum, zinc, brass, and copper-manganese alloys. An acidic cleaner may be used for brass, copper, or bronze alloys.
Once the cleaning step is complete, etching and passivating have to take place.The etching process consists of immersing the surface in a bath containing hydrofluoric acid (or hydrochloric acid and nitric acid, for some alloys). The contact time and concentration depend on the type of substrate and the desired surface roughness.
To then remove any etch residue and restore the active state of the surface, passivation should be carried out. The passivation process involves treating the surface in a solution containing a nickel ammoniated salt and other acid components.
Finally, the preparation stage is completed by rinsing the surface with deionised water and drying it with a soft clean cloth.
AS THE SECOND STEP, ACTIVATING
The activation stage provides a layer that is capable of accepting the nickel plating. Activation is achieved by immersing the object in a bath containing an activating solution.The activating solution typically contains a blend of sulphamic acid, nitric acid, and aqua ammonia. Alternatively, two stage activation may be used if desired. In this process, a pre-activation bath containing a sulphamic acid solution is used first, followed by an activation bath containing a blend of nitric acid and aqua ammonia.
Once the active layer is produced, the object is then washed with deionised water and dried.
THE THIRD STEP: PLATING
At this point, the plating stage can begin.Nickel plating is typically carried out in a nickel bath containing a nickel ammoniated salt. The nickel bath is heated to a temperature of between 130-160°F (54-71°C).
Before plating there are three factors that should be taken into consideration; the thickness of the plating deposit, the current density, and the duration of the plating cycle. The current density and plating time can be adjusted independently depending on the desired plating thickness. An excessively high current density may lead to a non-uniformly covered surface.
Once the plating cycle is complete, the plated item is then washed and dried.
After the plating process is complete, the surface should then be inspected for defects and non-uniform plating. If no defects are present the part can then be buffed and polished to select a desired final finish.
There are many variations of the plating process depending on the requirements of the application. Nickel plating can be performed with a variety of substrates and processes such as copper plating, brass plating, tin plating, silver plating, zinc plating, and electroless nickel plating.
Overall, nickel plating is an important process for many industries and its use is widespread. It has numerous advantages over other metal plating processes and is widely used in many different industries such as the automotive, electronic and medical industries. As long as the right processes are followed and the right materials are used, it can produce a consistently high-quality finish. 以上就是关于“工程镍镀浴配方”的文章，谢谢大家的阅读。
