A guide to understanding metal plating is often an excellent choice for everyone who is new to this. Since there are different kinds of metal plating, understanding every type can be helpful. It has been hundreds of years since metal plating was used, and it has also become one of the most crucial aspects of modern technology.
There are several reasons why metal plating has been encouraged and chosen by industries. The characteristics of metals are something that makes metal plating one of the most used technologies. Irrespective of the industry, these materials have their importance throughout.
What Do You Mean By Metal Plating?
Metal plating is a process that involves creating the outer coating with copper, nickel, chromium, or any other metal that has resistance to corrosion and improves the appearance. One of the most common processes is immersing this metal into an acidic solution with the use of an Anode and cathode.
The cathode is generally used for metal plating. It is the electrolysis cell where direct current is passed. The bath or solution is made with metal in the oxidized form. The Anode is generally the metal bar being properly plated.
During the electrolysis process, metal is generally deposited on metal from the dissolved bar. The principle of Faraday’s law governs the principle followed in the process. This procedure can result in easy deposition of parent metal from the metal.
Electroplating is most commonly used for a range of purposes. Following are some of them.
- Protection
- Special properties on the surface
- For decoration or enhancement
- For the mechanical or engineering properties
Irrespective of the type of metal, you can easily choose the plating process. Cadmium or zinc plating can become a great choice as it prevents rusting, whereas chrome and nickel plating helps to fight against wear and tear. Nickel, chrome, and zinc are the three most common industrially used plating metals. However, it is a need for you to choose the right process components.
What Are The Components Of The Metal Plating Process?
In the method of metal plating, you will find it creating the outer layer of copper, chromium, nickel, and other metal on the base material. It is generally done to improve the look of plated material and prevent it from corrosion. Plating is one of the methods that can be easily performed on all kinds of metals present in nature. However, the most common metals for industrial plating include chrome, nickel, and zinc.
Preparation for cleaning metal surfaces:
- Alkaline cleaning
- Electropolishing
- Oxide removal
Metal plating:
- Electroplating
- Electroless plating
- Immersion plating
Treatments for protection and finish:
- Anodizing
- Phosphating
- Chromate conversion
What Are The Common Steps For The Electroplating Process?
The electroplating process is a long process. The entire procedure generally takes 90 minutes for proper completion. However, it requires a person to have experience in handling metals. It is one of the most common processes used for steel plating and aerospace parts by making use of cadmium.
- The first necessary process is cleaning, where the surface is properly cleaned to make it free from contaminants. Since contaminants can quickly bond, this is a critical process to be taken.
- Properly rinse and then dry the metal if required.
- Acid cleaning is again an important step. Sandblasting by the use of aluminum oxide is generally used as it makes the surface rough so that plating metal gets improved adherence.
- Properly rinse the metal after completing the steps.
- Next to rinsing, choose conversion coating or the plating method.
- You have to rinse properly with water for one minute.
- Chemical rinsing is essential as it makes sure that the parts become resistant to rust.
- Rinse by using hot water.
What Are The Types Of Plating?
You have to understand the types of metal plating available. The following are the three most common types used for industrial processes.
1. Electroplating (Electrolytic Plating)
There is a range of metal plating types, and the electroplating process is probably one of the most common. This is a method of passing electric currents through the electrolyte solution. It has two terminals known as electrodes that are generally dipped into an electrolyte solution that connects to the power circuit.
Cathodes are generally the electrodes, and Anode is mostly used as coating material. When you find electricity flowing through a circuit, the electrolyte will split metal atoms from the Anode that gets deposited in a very thin layer on one of the cathodes.
Different kinds of metals can be chosen for the electroplating process. These include zinc, silver, gold, tin, nickel, chrome, copper, platinum, and lead.
2. Autocatalytic (Electroless Plating)
When you choose a metal plating procedure, one would generally go for electroplating. However, there are certain cases where you can find an alternative which is known as electroless plating. This procedure is simpler, cost-effective, and a great alternative for electroplating. The process is also called autocatalytic plating, which is a method of plating without the need for an external power source.
This process involves plating the material using an aqueous solution and then depositing it. It creates catalytic reduction to the path as this is a chemical process that does not need additional machinery or electricity.
Electroless plating is generally suitable for parts that have a hard surface and are resistant to corrosion. This is something that makes this procedure a great choice for the marine and oil industries. Some of the most common parts, like valves or pumps that are mostly subjected to corrosion, are created typically by the use of electroless plating technology.
3. Immersion Plating (Displacement Reaction)
This is a process where you need to apply an adhering layer of the nobler metal to the surface of another metal by dipping its path into a solution made with nobler metal ions. So, when you create metal parts from material like copper by putting it into the electrolyte solution, the iron of nobler materials can coat the parts of copper by releasing the electrons.
It can also be said as drip plating or metal replacement. Similar to electroless plating, where it does not require external current, this is also a chemical process. Unlike electroless plating, after the complete coating of the part, the metal deposition is then kept to a halt.
Immersion plating is a great choice for industries that are looking forward to creating a metal surface with improved resistance to corrosion and where. Besides, great electrical conductivity is another benefit. As it also alters reflectivity and appearance and has bonding capabilities, it can be an excellent choice for industries.
What Are The Applications Of Metal Plating?
There are several industries that make use of electroplating. It is a great choice for different industries. It can be used to create various things- from engagement rings to electrical antennas. Following are some of the major examples.
- Aerospace: Several components in airplanes are being electroplated to provide a sacrificial coating. It generally increases the path lifespan by decreasing corrosion. As aircraft components are subjected to substantial temperature changes and several other environmental factors, an additional layer of metal can add to the functionality without compromising its wear and tear.
- Home decor and art: You can find a lot of electroplated home decor available in the market. Generally, artisans choose biodegradable items like branches, bags, and flowers into long-lasting and durable pieces with the use of this process. Electroplating helps to preserve fine details and show off the items without going through decomposition.
- Automotive: Electroplating is the most common procedure used for creating customized parts, especially for concept vehicles. For example, hubcaps are created through electroplating type 20 concept vehicles. Even vehicle customization businesses and restoration companies choose to electroplate to apply on chrome, nickel, and several other finishes for motorcycle and car parts.
- Jewellery: Electroplating is probably one of the most commonly chosen processes in the precious metal and jewelry industry. Designers of this industry and manufacturers mostly choose this process to enhance the durability, aesthetic appeal, and color of the pendants, rings, bracelets, and a lot of other accessories.
- Dental and medical: Electroplating is generally used for adding resilience to the exterior in all sorts of dental and medical elements. Gold Plating is employed for creating tooth inlays, and it becomes helpful for different dental procedures. Some of the most common implanted parts include screws, joints, plates, and several others that are electroplated to make them cost and resistant. Even surgical and medical tools like radiological parts and forceps are all electroplated.
- Power: There are many solar components and electrical parts that were electroplated to improve their electrical conductivity. The manufacturers mostly electroplate the solar cell contacts and the different types of antennas. Wires are also sometimes electroplated with nickel, silver, and other metals. Gold plating is used to improve durability. Since gold can increase lifespan due to its ductility and conductivity, it can be a beneficial inclusion.
While there are several other applications of metal plating, these are the top few that frequently use the electroplating process. As there are a lot of benefits of metal plating, it is most commonly used by industries looking for durability, wear resistance, and improved electrical conductivity.
What Are The Plating Methods?
There is a range of metal plating methods being used by the industry. Here are the most common methods mentioned.
- Rack Plating Method: The first method is the rack plating method. In this method, the metal that would be plated is hung on a rack or frame. This is commonly seen to be a versatile approach that offers more control over the rest water and better drag out the metal rates.
- Barrel Plating: Barrel plating is another commonly used process that is done in a closed barrel. The procedure uses a unit to electroplate the smaller parts or the parts that require lower processing standards or levels. The use of rest water is higher along with the drag-out rates.
- Manual Plating: Manual metal plating is another method where each and every process is performed by experienced technicians. This is generally used for small-batch plating.
- Automated Plating: You can semi-automate or choose to completely automate the plating process. In the case of automated operation, experienced technicians required rack and unrack during the function of metal plating. The semi-automated procedure needs the manual use of rails and hoists. It is generally chosen by manufacturers for either a low production or larger part production.
What Are The Key Chemicals Used In The Process?
Different chemicals are used in the process to improve the results and increase the stability. Here We have categorized some of the major elements used in the process to help you get a better understanding.
- Acids and Bases used: Caustic and HCL.
- Coatings: Chromium, Cyanide, Cadmium, Gold, Silver, Bronze, Zinc, and Brass.
- Solvents: Trichloroethylene, Benzene, Tetrachloroethylene, TZE, and Tetrachloroethylene (perchloroethylene).
Understanding The Environmental Corrosion Testing
Metals are tested correctly in the environment to determine whether the electroplating method will be able to protect the metal from corrosion. The major challenge is stimulating the time that it takes for the occurrence. This is the reason why different manufacturers test for different types of tests to understand the quality that has been developed.
In some of the common cases, organizations set up both outdoor and indoor exposure stations. Several other approaches are also there for applying test metals on the surface that are exposed to different elements, like trucks that generally travel in cold regions. Some of the most common tests done on the metal include the following.
- Sulfur dioxide test: This is a common type where the material is generally placed in a certain chamber that has sulphur dioxide gas.
- Ascitic acid salt spray, which is also known as fog test: It is a process where the mist is mostly used containing acidic acid for accelerating the corrosive procedure.
- Electrochemical corrosion test: It is a process where the material is commonly placed in the electrolyte after it has become Anode. Certain conditions are being created by the manufacturer to enhance corrosion in a few minutes.
- Copper accelerated acetic acid salt spray or Cass test: It is the same as the fog test or acetic acid salt spray test. However, the only difference is the addition of copper salts.
- Humidity test: This is a kind of test on different types of metal plating. It is the corrosion test that is done to find whether the substance is reliable.
- Corrodkote test: Kaolin is a substance that is used on electroplated plates. The experienced technician will coat the substance. Kaolin contains copper nitrate, ferric chloride, and aluminum chloride. After it is properly dry, the material is then kept in a humid chamber.
Choose An Electroplating Kit
You can also choose a proper electroplating kit like the “Plug N’ Plate® Workshop Electroplating Kit.” These kits include everything you need to plate metals with other metals like copper, nickel, tin, brass, bronze, gold, silver, chrome, and a lot more.
It also includes the parts, technical support, and a proper instruction manual for the user. This is a perfect choice for metal plating on smaller parts.
Conclusion
So this is everything that you need to know about metal plating. No wonder metal plating is one of the most commonly chosen techniques in different industries to create highly resistant substances.
Whether it comes to improving longevity, resistance to wear and tear, or getting corrosion resistance and proper appearance, metal plating is one of the first and most used techniques. Hence, whether it is the jewellery industry, art and decor, or aerospace, metal plating is a common and prevalent technique.
