Notes

Slide Show

Outline

1
2
3
4
5	Electroplating : Electrochemical process for depositing a thin layer of metal on, usually, a metallic base Electroplating Objective Objects are electroplated to prevent corrosion, to obtain a hard surface or attractive finish, to purify metals (as in the electrorefining of copper), to separate metals for quantitative analysis
6	Electroplating makes use of an electrolytic cell, electricity to bring about a chemical change.
7	work?How does electroplating anode out of copper and spoon as the cathode. The electrodes are placed in an aqueous solution of CuSO₄ and a battery pumps electrons from anode to cathode.
8	. The copper anode undergoes oxidation; Cu⁺² from solution migrates to the cathode, undergoes reduction, and deposits on the spoon.
9	III- SURFACE TRETMENTS an anode (positively charged electrode), which is the source of the material to be deposited a cathode which is the substrate (the negatively charged electrode) to be coated.
10	In the case of materials such as gold, the anode is not sacrificial (gold does not dissolve easily !), Plating is an oxidation-reduction reaction, where one material gives up electrons (gets oxidized) and the other material gains electrons (gets reduced). The anode is the electrode at which oxidation occurs, and the cathode is the electrode at which reduction occurs.
11
12	IV- THEORY OF ELECTROPLATING Plating is governed by Faraday's Laws that state: 1. The weight of a substance formed at an electrode is proportional to the amount of current passed through the cell.
13	.2. The weights of different substances produced at an electrode by the same amount of current are proportional to their equivalent weights.
14	V- COATING OBJECTS The object to be coated is placed in a solution, called a bath, of a salt of the coating metal, and is connected to the negative terminal of an external source of electricity
15	Teapots are electroplated with a thin layer of silver to protect them from corrosion and to give them an attractive finish
16	VI- Autocatalytic plating Also known as electroless plating is a plating process which involves deposition without any current applied. The process is a chemical reaction and is autocatalytic.
17	VII- TIN ELECTROPLATING The technique of fusing electrodeposited tin alloy coatings was originally used by the U.S. aerospace industry on circuit boards and has been increasingly applied to the production of high-quality printed circuit assemblies in automotive and other industries.
18
19	Electroplating Equipments:
20
21	Fume Scrubber
22	Arm type plating machine in circle shape
23	Over-all view of Arm type automatic line
24	Racks with Arm type plating
25