Hey, Today we will learn about the one of kind of non-conventional machining process, that is Laser beam machining process means what it is, Its, basic principle, construction, working, advantages as well as disadvantages and its uses, so, let’s start the topic with briefly understanding about the laser.
What is laser ?
- Laser is the amplification of light.
- The full form of laser is Light amplification by stimulated emission of radiation. It means the laser is the photons that are emitted from the energized electrons.
What is Laser beam machining (LBM)?
1] Laser beam machining is the machining process in which The heat energy produced by the laser is used to remove the material from the work-piece surface.
2] It is the type of the non conventional machining process.
3] LBM is commonly used for brittle material.
Laser beam machining working principle
- Laser beam machining works on laser produced by the ruby crystal for the machining.
- When the laser falls on the work-piece surface,Then the heat energy produced by this laser melts & vaporizes the material surface.
Laser beam machining diagram
Construction
- Power supply
- Xenon lamps
- Ruby crystal
- Focus Lense
1) Power supply:- Power supply supplies the high voltage power (Around 1Kw-10Kw) to the xenon lamps to produce light.
2) Xenon lamps:- Xenon lamps takes power from the power source & produce light. This light from xenon lamp energizes the electrons of the crystal atoms.
3) Ruby crystal:- The Ruby crystal produces the laser by absorbing the light from xenon lamps. This crystal consists of large number of atoms. When light from xenon lamps falls on the crystal, Electrons in the Crystal get energized & produce photons or light energy.
4) Focus Lens:- In the laser beam machining process, the lens is used to focusing the all light energy or photons that come from the ruby crystal on the workpiece.
Working of Laser beam machining
1) When the high voltage power source is on, Xenon lamps start producing light.
2) The electrons in the crystal atoms starts absorbing the light from the xenon lamps.
3) Due to light, Electrons get energized to a high energy level from the ground state & start emitting more photons with comes to the ground state.
4) The upper reflected mirror reflects all these photons to the crystal & the lower partial reflected mirror reflects some photons and releases some photons throughout itself.
5) After Photons from the ruby crystal falls on the lens. The focus lens focuses all the photons and produces laser on the workpiece.
6) When this laser falls on the workpiece, Due to the laser heat, The workpiece surface gets melts & vapourises.
hence in such way, laser beam machining works on laser produced by the ruby crystal for the machining.
Advantages of LBM
The advantages of Laser beam machining are as follows:-
- Very good surface finish can obtained.
- No problem of tool wear.
- Capacity of machining complex shapes.
- No direct contact between tool & work-piece.
- High accuracy of machining.
Disadvantages of LBM:-
The disadvantages of the Laser beam machining are as follows:-
- It has limitation of thin sheet, means it cant drill deep holes.
- Material removal rate is very less.
- Xenon lamp has less life period.
Laser beam machining applications:-
The use of Laser beam machining is as follows:-
- It is uses for drilling, cutting purpose in automobile, aerospace & so many industries.
- It is used in drilling small size holes.
Difference between electron beam machining and laser beam machining:-
| Sr. No. | Electron beam machining | Laser beam machining |
|---|---|---|
| 1 | It uses heat energy produced by high velocity, focused electron beam for the machining. | It uses heat energy produced by the laser beam for machining. |
| 2 | Electron gun is the source of electron beam. | Xenon lamp is the source of laser beam. |
| 3 | Material removal rate is low. | Comparatively high material removal rate. |
| 4 | X-rays are generates during machining which are dangerous for operator. | X-rays are not generates during machining. |
| 5 | This machining process carried out in vacuum chamber since if electrons comes in contact with particles in atmospheric air then electron will loose their energy. | No need of vacuum chamber for machining. |
| 6 | High skilled operators required. | Less skilled operators can handle. |
