Electroplating

By: Matthew Nerhing

What is Electroplating?

• Electroplating- It is the deposition of a thin layer of metal on a surface by an electrical process involving oxidation-reduction.

Electroplating uses electrical currents to reduce cations from the object to coat the conductive object with some sort of material.

Objects get placed into the tanks that are getting a thin layer of a certain material such as silver, gold, and bronze through an electrical process

Electroplating

• 3 examples-

• 3 applications- Aesthetic protection, weather protection, and rust protection

zinc electroplating silver electroplating , and gold plating

How does Electroplating Work?• You put the metallic object you want to plate with the certain metal• fill the cell with a solution of a salt of the metal to be plated• A wire is connected to the object, and the other end of the wire is attached to the negative pole of a

battery.• A rod made of nickel is connected to the positive pole of the battery with the red wire• Because the object being plated is negatively charged, it attracts the positively charged Ni++ ions. These Ni++

ions reach the object, and electrons flow from the object to the Ni++ ions. For each ion of Ni++, 2 electrons are required to neutralize its positive charge and 'reduce' it to a metallic atom of Ni0

• Meanwhile back at the anode, electrons are being removed from the Nickel metal, oxidizing it to the Ni++ state. Thus the nickel anode metal dissolves as Ni++ into the solution, supplying replacement nickel for that which has been plated out, and we retain a solution of nickel chloride in the cell.

• As long as the battery doesn't go dead, nickel continues to dissolve from the anode and plate out onto the cathode.

Electroplating

• The process used in electroplating is called electro deposition• The part to be plated is the cathode of the circuit. In one technique, the anode is

made of the metal to be plated on the part. Both components are immersed in a solution called an electrolyte containing one or more dissolved metal salts as well as other ions that permit the flow of electricity.

• A rectifier supplies a direct current to the anode, oxidizing the metal molecules that comprise it and allowing them to dissolve in the solution. At the cathode, the dissolved metal ions in the electrolyte solution are reduced at the interface between the solution and the cathode, such that they "plate out" onto the cathode.

• Also, Electroplating changes the chemical, physical, and mechanical properties of the work piece

Review Questions

• What is electroplating?• Why is electroplating used today?• Give an example of electroplating?

Cites

• Book- • Internet-http://en.wikipedia.org/wiki/Electroplating

• Internet- http://www.finishing.com/faqs/howworks.html