Electroless nickel-boron plating, also known as autocatalytic nickel plating, is a chemical method of coating electroplated nickel-boron that is characterized by the absence of electric current.The plating is an autocatalytic reaction that takes place in an aqueous solution, which consists of a nickel salt, a reductant, a boron compound and a buffer.The reaction does not require the application of external electricity in order to deposit the nickel-boron layer onto the substrate.
The electroless nickel-boron plating process is usually started with a chemical cleaning step, which involves the use of acid to dissolve and remove the natural oxide layer that forms on the surface of the components to be plated.After this, the components are immersed in an aqueous solution containing a reductant and a nickel salt.The reductant reduces the nickel salt to metallic nickel and deposits it onto the surface of the components.
The plating solution also typically contains a boron compound such as borax, which is an important component of the reactants in the autocatalytic reaction.The boron compound serves to increase the hardness of the nickel deposit, which makes the coating more wear-resistant and improves its corrosion protection properties.
In addition to the nickel salt, the reductant and the boron compound, the aqueous solution may also contain a buffer to help maintain the acidic/alkaline balance of the solution.Buffers play an important role in electroless nickel-boron plating because they help to prevent the surface of the components from becoming negatively charged during the plating process.
Once the components are immersed in the solution, the reaction begins and the nickel-boron plating is deposited onto the surface of the components.The process can take several minutes or several hours depending on the desired plating thickness and other factors.
The deposition process is typically followed by a post-plating treatment with a reducing agent, which is necessary to remove any excess nickel or boron from the surface of the components.Finally, the post-plated parts are typically rinsed with deionized water to remove any remaining contamination from the plating solution.
Electroless nickel-boron plating provides several advantages over traditional electroplated nickel-boron plating processes.It eliminates the need for an electrical current and therefore reduces the risk of short-circuiting, which can cause damage to the plated components.In addition, it produces a coating that is denser and more uniform than traditional methods, which helps to provide superior corrosion resistance and wear-resistant properties.
Ultimately, electroless nickel-boron plating is a cost-effective and reliable method of depositing nickel-boron layers onto substrates, which makes it an attractive option for many engineering applications.
