Electroplating is a process that helps the deposition of metallic coatings on the surface of an object. The electroplating process utilises electric current. In this process a negative charge is given to the object to be plated and then immersing that object in a positively charged ionic solution. The positive ions are attracted to the negatively charged ions, enabling the deposition to take place.
Electroplating has been used for so many years. It has also many applications in the engineering field. It is extensively used in the electronics industry where plating with silver and gold is required. It remains the most widely used of processes. Besides these precious metals, electroplating is also used to deposit aluminium, chromium nickel and other metals. Electroplating changes the mechanical, physical and chemical state of the piece being plated. Chemical changes help improve the corrosion resistance of these plated pieces. Physical changes in any plated item are obvious. In some plated items there is a change in the surface’s hardness and tensile strength. Knowing the effects of electroplating, most designers of parts are able to use these characteristics of the plating materials while retaining the advantages of the basic material.
This process has also been used to deposit metal on plastics. This has been of great help to the automobile industry. Electroplating has allowed trim and other non-structural parts to be made of plastic and coated like metal to retain the original aesthetics. Reduced weights have resulted in the saving of fuel and other benefits like reduced costs. Chromium plating of brass is also widely used in plumbing fittings. This allows the excellent properties of brass for use in water to be coupled with the ease of maintenance that chromium plating does give to these fittings.
The thickness of plating achieved through this process is about 0.05mm. It gives metal-coated objects a resistance to rusting and protection from wear. It also prevents corrosion and greatly improves the objects appearance. The use of metal deposits from rhodium, palladium and platinum gives metal parts a very hard surface that becomes almost impervious to corrosion. Thicknesses can be increased by increasing the time of the process.
Electroplating allows makers of metal products to use inexpensive materials for the major mass of the part. It also enables them to add other properties like corrosion resistance and hardness. This can be achieved by using the right alloy forming material through the coating. In many cases, the finishes so obtained are purely decorative. It is extremely important that the parts to be electroplated are free from all dirt, oil and grease. Otherwise, the process can be affected and deposition will not take place. The cleaning process follows three steps of cleaning. This includes cleaning, treating the part and then rinsing it. Cleaning solutions can be acidic or alkaline depending on the contamination. Parts can then be treated by modifying their surface or putting them through a process of hardening. Rinsing removes all traces of the cleaning solutions and prepares the part for the final electroplating process.
The electroplating process is constantly being evolved to create technological innovations that lead to cost reductions and additions to the required properties of the plated materials.