Category Science

Objects may be electroplated for protection or to enhance their appearance. Very often, the object itself is made from a much cheaper material than the plating. Plating may protect the material underneath. Tin plate on steel cans stops the steel from corroding. Chromium Plating was once common on cars to prevent bumpers and headlights from rusting.

Electroplating is the process of using hydrolysis for plating one metal onto another. The process of electroplating is extensively used to modify the surface properties such as rust resistance and abrasion of objects. This process involves the use of an electric current, which is passed through the electrolyte (solution) containing two terminals called as electrodes. These electrodes are connected through a circuit with the power supply or battery. On passing an electric current through the circuit, the electrolyte in the solution splits up and some atoms from the metal are deposited on the top of one of the electrodes in the form of a thin layer. Metals like copper, gold, nickel, zinc, silver, cadmium, chromium, and tin are used in the electroplating process. This process is considered to be an important aspect in the production of electrical and electronic appliances, as it provides a coating on the surface of the metal of components used in these appliances. This helps in improving corrosion resistance, improves the conductivity of electricity, and enhances the solderability of the substrates. There are various applications of electroplating.

Mass plating is one of the types of electroplating that is used to plate a large volume of components in little to no time. To perform mass plating, a barrel is loaded with parts and then placed inside a container, which is filled with the coating material. Following this, the barrel is rotated to ensure that all the components inside the barrel are evenly coated for protection from corrosion. Mass plating is one of the most common types of electroplating and is one of the processes with the maximum applications. However, the mass plating process also brings parts in contact with one another, which can create an adverse effect on the coatings. So, another electroplating process can be used for components that require a high degree of aesthetic appeal. Following are the common examples of parts or components that undergo these types of electroplating: Bolts, Nuts, Screws, Washers, Pins and Electrical Connectors.

Rack plating is used to electroplate large, complex, and brittle parts that are tough to plate using other methods. In this process, parts are mounted to a “rack” and then immersed in a plating solution. This method provides uniform distribution of coating since the rack holds different parts that are plated at the same time. These types of electroplating processes are common in aluminum and zinc, and chrome and nickel are commonly used as plating solutions. Shape, size, and quantity of the parts must be considered before settling on this process.

In continuous plating items like tubes, wires, and strips are plated by running them continuously through a plating solution, one after the other. This process involves the even distribution of the coating material, such as zinc, aluminum, or tin, onto a metal like steel. It helps to enhance the corrosion resistance, appearance, wear, or other properties of a metal. Continuous plating provides even distribution of the coating and the electric current.

Electroplating uses electrolysis to deposit a thin layer of metal on another substance. The item to be plated is used as one electrode. Copper, silver, tin and chromium are often applied to surfaces in this way.

Electroplating is also known as electrode position. As the name suggests, the process involves depositing material using an electric current. This process results in a thin layer of metal being deposited onto the surface of a work-piece called the substrate. Electroplating is primarily used to change the physical properties of an object. This process can be used to give objects increased wear resistance, corrosion protection or aesthetic appeal, as well as increased thickness.

While electroplating may seem like advanced technology, it is actually a centuries-old process. The very first electroplating experiments occurred in the earth 18th century, and the process was officially formalized by Brugnatelli in the first half of the 19th century. After Brugnatelli’s experiments, the electroplating process was adopted and developed across Europe. As manufacturing practices advanced over the next two centuries through the Industrial Revolution and two world wars, the electroplating process also evolved to keep up with demand, resulting in the process Sharretts Plating Company uses today.

The electroplating process uses an electric current to dissolve metal and deposit it onto a surface. The process works using four primary components:

Anode: The anode, or positively charged electrode, in the circuit is the metal that will form the plating.

Cathode: The cathode in the electroplating circuit is the part that needs to be plated. It is also called the substrate. This part acts as the negatively charged electrode in the circuit.

Solution: The electrodepositing reaction takes place in an electrolytic solution. This solution contains one or more metal salts, usually including copper sulfate, to facilitate the flow of electricity.

Power source: Current is added to the circuit using a power source. This power source applies a current to the anode, introducing electricity to the system.

Once the anode and cathode are placed in solution and connected, the power supply supplies a direct current (DC) to the anode. This current causes the metal to oxidize, allowing metal atoms to dissolve in the electrolyte solution as positive ions. The current then causes the metal ions to move to the negatively charged substrate and deposit onto the piece in a thin layer of metal.

As an example, consider the process of plating gold onto metal jewelry. The gold plating metal is the anode in the circuit, while the metal jewelry is the cathode. Both are placed in solution and DC power is supplied to the gold, which dissolves in solution. The dissolved gold atoms then adhere to the surface of the base metal jewelry, creating a gold coating.

Electrorefining, as the word suggests, is a way of purifying metals by using electrolysis. Copper can be purified by making the impure copper the anode in an electrolyte of copper sulphate. The cathode is made of pure copper. When an electric current is passed through the copper sulphate, positively charged copper ions from the anode are attracted to the cathode of pure metal. The impurities, which may be tiny amounts of other metals, such as mercury, gold and silver, fall to the bottom of the electrolyte.

Electro refining is one of a collection of electrochemical processes which are primarily concerned with the extraction of metals from their ores and or the subsequent refining of the metals to high purity.

The main advantages of electro refining processes are they are designed to handle a wide variation in the quality of the base scrap and conversely can provide a particularly high purity of end product material.

Electrochemical processing is used both in the primary extraction of metals from their ores and in the subsequent refining of metals to high purity. Both operations are accomplished in an electrolytic cell, a device that permits electrical energy to perform chemical work. This occurs by the transfer of electrical charge between two electrodes immersed in an ionically conducting liquid (electrolyte) containing metal dissolved as positive ions.

At the negatively charged cathode the metal cations acquire electrons (are reduced), and deposit as neutral metal atoms. At the positively charged anode there are two possible reactions, depending upon the type of cell. In an electrowinning cell the dissolution of the anode metal itself occurs. The more noble metals such as copper and zinc are electrolyzed from aqueous electrolytes, whereas reactive metals such as aluminum and magnesium are electrolyzed from electrolytes of their fused salts.

In an Electrorefining process, the anode is the impure metal and the impurities must be lost during the passage of the metal from the anode to the cathode during electrolysis, i.e. the electrode reactions are, at the anode: M ? Mn+ + ne- and at the cathode: Mn+ + ne- ? M.

Usually they are part of a larger operation to separate and recover pure metals from both scrap and primary ores. Therefore, the process must be designed to handle a variable-quality metal feed and lead to a concentration of all the metals present in a form which can be treated further. Electrorefining often provides a particularly high purity of metal.

Electrorefining processes using a molten salt or non-aqueous electrolyte are used and, indeed, are the subject of further development. This is due to the possibilities they offer for increasing current densities and refining via lower oxidation states not stable in water (e.g. refining of copper via Cu+ would almost halve the energy requirement). However, aqueous processes presently predominate due to their ease of handling, more developed chemistry and familiarity with aqueous process liquors and electrolytes.