laser beam machining

LASER BEAM MACHINIG

Laser is an electromagnetic radiation. It produces monochromatic light which is in the form of an almost collimated beam that can be focused optically on to very small spots of less than 0.002 mm dia.The word laser stands for light amplification by stimulated emission of radiation

PRINCIPLE OF LASER:-

Let us consider that the atoms of a medium are at ground state.When a quantum of energy from light sources is made to fall on this medium, it causes absorption of radiation by the atoms of the medium to jump to the upper energy level. The atoms in the upper energy level are then said to be in an excited state.

The atom in an excited state immediately begins to drop spontaneously to the metastable(intermediate) state.From the metastable state the atom emits photon at randombefore it falls to the original energy level. This radiation of photons is known as spontaneous emission which is extremely rapid.

However, in the presence of light of the appropriate frequency stimulated emission will occur in the upper energy level when the atoms will begin to emit and chain reaction will occur by causing more to emit and the whole avalanche dump down together. This is called “Lasing action.”

ACCURACY:-

The laser is best used for cutting as well as for drilling.In order to achieve the best possible results in drilling, it is imperative that the material be located within a tolerance of ±0.2mm of focal point.

APPLICATION OF LBM:-

Laser machining process is at present found to be suitable only in exceptional cases like machining very small holes & cutting complex profiles in thin, hard materials like ceramics.It is also use in partial cutting or engraving