Laser beam welding,principle,working, applications, advantages and disadvantages.

Principle:

        Light energy is converted into heat energy. Here, the light energy is produced from the laser source such as ruby rod in the form of 

monochromatic light. 

Working: 

Due to electrical discharge from the capacitors, the flash tube convens the electn'cal energy into light flashes. When ruby rod is exposed to the intense light flash, the chromium atoms of the crystal excited and pumped to a high energy level beam. This high energy level is immediately reduced to intermediate and dropped to original state with the evolution of red fluorescent light. 

        The laser light is not only intense ut also can be readily focused without loss of intensity. The laser light is focused by the focusing lens to the work piece in the form of coherent monochromatic light. When this light energy is impacted to the work piece, it will convert into heat energy. This heat energy is sufficient to melt the materials to be welded. The various laser forms are: 

1. Liquid laser, 

2. Gas laser, 

3. Ruby laser, and 

4. Semi conductor laser. 

Advantages: 

1. It is used in glass and plastics.  

2. There is no need of electrodes and power. 

3. Even very small holes can also be welded. 

4. There is no vacuum requirement such as electron beam. 

5. Accuracy is greater. 

6. There is no heat loss. 

7. Neat and clean surface finish can be obtained. 

Disadvantages: 

1. Welding process is slow. 

2. Limited depth of weld can be done. 

3. It is not suitable for large production 

Applications: 

1. Thin metals about 0.5 to 1.5 mm thick can be welded. 

2. It is very much useful in electronic components welding. 

3. It is used in aircraft components joining. 

4. It can joint dissimilar metals. 

5. It is very much useful in joining metal alloys.