300+ [REAL TIME] Electroplating Interview Questions

1. Explain Electroplating?

Electroplating is the process of plating one metal onto another by hydrolysis, most commonly for decorative purposes or to prevent corrosion of a metal. There are also specific types of electroplating such as copper plating, silver plating, and chromium plating.

2. How Can Electroplating Be Done?

Electroplating involves passing an electric current through a solution called an electrolyte. This is done by dipping two terminals called electrodes into the electrolyte and connecting them into a circuit with a battery or other power supply.

3. What Is Electroplating Used For?

Electroplating is widely used in various industries for coating metal objects with a thin layer of a different metal. The layer of metal deposited has some desired property, which the metal of the object lacks. … Electroplating has wide usage in industries. It is also used in making inexpensive jewelry.

4. What Is Electro Deposition?

Electro deposition is the process of coating a thin layer of one metal on top of a different metal to modify its surface properties.

5. What Is Nickel Plated Steel?

Nickel electroplating is a technique of electroplating a thin layer of nickel onto a metal object. The nickel layer can be decorative, provide corrosion resistance, wear resistance, or used to build up worn or undersized parts for salvage purposes.

6. What Is A Nickel Strike?

A strike layer, also known as a flash layer, adheres a thin layer of high-quality nickel plating to the base material. Once up to 0.1 micrometers of nickel coats the product, a lower quality current density is used to improve the speed of product completion.

7. What Is Flash Plated?

Flash Gold Plating. Flash gold plating is when jewellery is given a very thin coating of gold, just enough to give a colour and even finish. It is commonly used to plate costume jewellery or display items.

8. Which Metals Are Used In The Electroplating Process?

Metals commonly used in electroplating include zinc, copper and tin, as well as precious metals such as gold, silver and palladium. Plating can occur with individual metals or in various combinations (alloys) that can provide additional value to the electroplating process. Price, substrate composition and desired result are key factors when determining the most appropriate electroplating process.

9. What Are The Uses Of Electroplating?

Uses of electroplating
: In addition to improving the appearance of the substrate, electroplating is used for multiple other purposes. A primary application is to improve the work piece’s resistance to corrosion. The plated layer will often serve as a sacrificial coating, meaning it will dissolve prior to the base material. Other common uses of electroplating include:

• Building the thickness of a metal surface.
• Increasing wear resistance.
• Improving electrical conductivity — such as when plating a copper layer onto an electrical component.
• Preparing surfaces for enhanced adhesion prior to painting or e-coating.
• Reducing friction.
• Protecting against surface abrasions.
• Improving surface uniformity.

10. What Is The Purpose Of Electroplating?

The Purposes of Electroplating:

Appearance
: One the important purpose of electroplating is that, it enhances appearance of the objects. Electroplating gives smooth and attractive finish to the crude metal objects. One of the examples from our day to day lives is chromium plating on automobiles and kitchen appliances which gives them an up market appeal. Also, we see that thin plating of precious metals such as gold or silver on less valuable metal make wide use in expensive jewellery making.

Protection
: The basic purpose of electroplating is to protect the metal from environmental and atmospheric conditions such as corrosion for example iron is likely to get eroded easily, in order to protect it from rusting, coatings of metal such as magnesium, zinc and aluminium are applied. 

Special surface properties
: The other purpose served by it incorporating some special surface properties. For example, chromium and nickel plating is used when hardness is required.

Engineering or mechanical properties
: It also serves in providing many mechanical properties to the metals which it lacks such as magnetic properties, resistance, light absorption etc. For example, copper or brass connectors are silver plated in order to increase the electrical conductivity.

11. Explain The History Of Electroplating?

History of Electroplating : 
Electroplating was first discovered by Luigi Brugnatelli in 1805 through using the electrodeposition process for the electroplating of gold.  However his discovery was not noted as he was disregarded by the French Academy of Science as well as Napolean Bonaparte. But a couple of decades later, John Wright managed to use potassium cyanide as an electrolyte for gold and silver. He discovered that potassium cyanide was in fact an efficient electrolyte.

The Elkington cousins later in 1840 used potassium cyanide as their electrolyte and managed to create a feasible electroplating method for gold and silver. They attained a patent for electroplating and this method became widely spread throughout the world from England. Electroplating method has gradually become more efficient and advanced through the use of more eco-friendly formulas and by using direct current power supplies.

12. What Are The Types Of Electroplating?

Types of Electroplating : 
There are different processes by which people can electroplate metals such as by mass plating (also barrel plating), rack plating, continuous plating, and line plating. Each process has its own set of procedures which allow for the ideal plating.

Mass Plating : 
It’s not ideal for items that are detailed as it is not effective in preventing scratches and entanglement. However, this process plates a mass amount of objects efficiently.
Rack Plating : 
More expensive than mass plating, but effective for either large or delicate parts. Often has parts submerged in solutions with “racks”.
Continuous Plating : 
Parts such as wires and tubes are continuously passing anodes at a certain rate. This process is a bit cheaper.
Line Plating : 
Cheaper, as fewer chemicals are used and a production line is used to plate parts.

13. Why Is It Important To Prepare The Surface Before Beginning Electroplating?

It is important to prepare the surface before beginning the procedure because sometimes there is contamination on the surface that could lead to bad electroplating results.

14. What Are The Categories Of Electroplating Coating?

Most electroplating coatings can be separated into these categories:

Sacrificial Coating
: is used primarily for protection. The metal used for the coating is sacrificial, being used up, in the reaction. Common metals include: zinc and cadmium (now forbidden in many countries).

Decorative Coating
: is used primarily for appeal and attractive purposes. Common metals include: copper, nickel, chromium, zinc and tin.

Functional Coatings
: are coatings done based on necessity and functionality of the metal. Common metals include: gold, silver, platinum, tin, lead ruthenium, rhodium, palladium, osmium, and iridium.

Minor Metals
: are normally iron, cobalt, and indium because they are easy to plate, but are rarely used in plating.

Unusual metal Coating
: are metals that are even more rarely used for plating than the minor metals. These include: As, Sb, Bi, Mn, Re, Al, Zr, Ti, Hf, V, Nb, Ta, W, and Mo.

Alloy Coatings
: An alloy is a substance that has metallic properties and is made up of two or more elements. These coatings are made by plating two metals in the same cell. Common combinations include: gold–copper–cadmium, zinc–cobalt, zinc–iron, zinc–nickel, brass (an alloy of copper and zinc), bronze (copper–tin), tin–zinc, tin–nickel, and tin–cobalt. 

15. How Electroplating Works?

Electroplating works like a galvanic cell in reverse. An electrical current reduces cations from a solution so that they can coat a conductive material with a thin layer.

16. What Is Electroless Deposition?

Electroless plating, also known as chemical or auto-catalytic plating, is a non-galvanic plating method that involves several simultaneous reactions in an aqueous solution, which occur without the use of external electrical power. It is mainly different from electroplating by not using external electrical power.

17. What Is Electroless Nickel Plating?

Electroless nickel plating (EN) is an auto-catalytic chemical technique used to deposit a layer of nickel-phosphorus or nickel-boron alloy on a solid workpiece, such as metal or plastic. The process relies on the presence of a reducing agent, for example hydrated sodium hypophosphite.

18. How Does The Process Of Electroplating Work?

Electroplating is the process of plating one metal onto another by hydrolysis, most commonly for decorative purposes or to prevent corrosion of a metal. There are also specific types of electroplating such as copper plating, silver plating, and chromium plating.

19. What Are The Advantages And Disadvantages Of Electroplating?

Electroplating is the process of plating one metal over another. It is done for various purposes, most commonly for imparting corrosion resistance and decorative appearance.

Advantages of this process:

Corrosion resistance:
a corrosion-prone substance such as iron can be coated with a layer of non-corrosive material, thereby protecting the original material.

Decorative items:
shine and luster can be imparted to otherwise dull surfaces. This makes for great decorative items.

Cheaper ornaments:
instead of making ornaments out of gold or silver, one can make them using cheaper metals and electroplate the ornaments with gold. This reduces the cost of ornaments greatly.

improving mechanical characteristics
: electroplating can also improve the mechanical characteristics of metals.

Disadvantages of this process :

Non-uniform plating:
electroplating may or may not be uniform and this may result in a substandard appearance of the plated material.

Cost
: the process is costly and time consuming.

Pollution potential:
the electroplating solution, after use, needs to be disposed off safely and is a cause of environmental concern.

20. Give An Example Of Electroplating?

Silver electroplating, for example, is often used on copper or brass connectors due to its superior conductivity. Other precious metals such as gold and palladium plating are commonly used for switchgear in the telecommunications industry.