Laser Beam Machining | What Is Laser Beam Machining?

Definition of Laser Beam Machining

The Full Name of the Term, “Laser” Is A Light light. light Amplification by Stimulated Emission of radiation. The Basic Elements Of LBM, Light Stimulated emission of Radiation The full form of Laser

A laser beam machining is a non-conventional machining method in which the operation is performed by laser light. of metallic and non-metallic materials. In this process, a laser beam of high energy is made to strike on the workpiece, the thermal energy of the laser gets transferred to the surface of the w/p (workpiece). The heat so produced at the surface heats melts and vaporizes the materials from the w/p.Light amplification by stimulated emission of radiation is called LASER.

What Is Laser Beam Machining

Light amplification is the key element for producing lasers. The light amplification is a result of stimulated emission due to incident photons of high energy.

There are three main components to any laser system: laser medium means for exciting the laser medium to the state of excitation which is the source of energy, and the optical feedback system. Some other provisions such as cooling system for the mirrors, a guiding system for guiding the laser beam, etc., are also equally important.

The laser medium can be liquid such as die; solid as for instance neodymium-doped yttrium-aluminum-garnet; gas such as CO2, Ne. Laser light is different from ordinary light in the manner that these are highly directional, has better focusing characteristics and has high power density.

These different and unique aspects of the laser light make it suitable for the processing of materials. The most commonly used lasers for laser beam machining (LBM) applications are Nd-YAG and CO2 lasers. The wavelength of CO2 lasers in the infrared region is 10 lm. The CO2 laser possesses better efficiency, high beam power, and good quality.

Types of Laser

On the basis of the media used for the production of the laser it is classified as

1. Gas Lasers: In these types of laser, gases are used as the medium to produce lasers. The commonly used gases are He-Ne, argon and Co2.
2. Solid State Lasers: The media of the solid state lasers are produced by doping a rare element into a host material.

Ruby laser is an example of solid state laser in which ruby crystal is used as medium for the generation of laser beam.

The other media used in the solid state lasers are

(i) YAG: For yttrium aluminum garnet which a type of crystal.
(ii) Nd:YAG – Refers to neodymium-doped yttrium aluminum garnet crystals

Main Parts used in the laser beam machining

The various main parts

1. A pumping Medium: A medium is needed that contains a large number of atoms. The atoms of the media are used to produce lasers.
2. Flash Tube/Flash Lamp: The flash tube or flash lamp is used to provide the necessary energy to the atoms to excite their electrons.
3. Power Supply: A high voltage power source is used to produce light in flashlight tubes.
4. Capacitor: Capacitor is used to operate the laser beam machine at pulse mode.
5. Reflecting Mirror: Two types of mirror are used, first one is 100 % reflecting and other is partially reflecting. 100 % reflecting mirror is kept at one end and partially reflecting mirror is at the other end. The laser beams comes out from that side where partially reflecting mirror is kept.

The Basic Elements Of Laser Beam machining (LBM)

Laser Rod or Tube (Which is Made Of Glass Coated with reflecting material)
A flash lamp (which is the source of energy)
A pair of mirrors (One at each end of the tube)
An Amplifying Source
A source of power supply (A.C or D.C)
A Cooling System
A lens (which is the Focusing Source)

Working Principle of Laser Beam Machining (LBM):

The material removal mechanism in the LBM(laser beam machining) technique can be categorized into different stages: melting, vaporization, and chemical degradation. The high-energy laser beam is absorbed by the workpiece surface in the form of thermal energy. This high thermal energy transforms the volume of the workpiece material into a molten, vaporized, or chemically changed state. The high-pressure gas then assists in removing the molten or the vaporized material.

The physics of the LBM is pretty complex owing to losses taking place at the workpiece material in the form of reflection and scattering. The process progresses

A very high-energy laser beam is produced by laser machines.
Focuses on the workpiece to mechanize this laser beam produced.
When the laser beam hits the surfaces of the W/P, the thermal energy of the laser beam is transferred to the surfaces of the W/P.
It heats, melts, evaporates, and eventually makes the material a workpiece.
This is how laser beam machining works.
It works on the principle that when a high-energy laser beam strikes the surfaces of the workpiece.
The heat energy contained by the laser beams is transferred to the surface of the w/p.
This heat energy absorbed by surface heat melts and evaporates the material w/p. Machining of materials in this way is done using laser beams.

It works on the principle that when a high energy laser beam strikes the surface of the workpiece. The heat energy contained by the laser beam gets transferred to the surface of the w/p. This heat energy absorbed by the surface heat melts and vaporizes the material from the w/p. In this way the machining of material takes place by the use of laser beam.

Diagram of Laser Beam Machining

Laser Beam Machining Working Principle: — Diagram of Laser Beam Machining

Advantages of Laser Beam Machining:

The Following Advantages of Laser Beam Machining Are:
It can be focused on very small diameters. It produces a huge amount of energy, about 100 MW per square mm area.
It is capable of producing a very accurately placed hole.
Laser beam machinings have the ability to cut or engrave almost all types of materials when conventional machining processes fail to cut or engrave any material.
It can be focused to a very small diameter.
It produces a very high amount of energy, about 100 MW per square mm of area.
It is capable of producing very accurately placed holes.
Laser beam machining has the ability to cut or engrave almost all types of materials, when traditional machining process fails to cut or engrave any material.
Since there is no physical contact between the tool and workpiece. The wear and tear in this machining process is very low and hence it requires low maintenance cost
This machining process produces object of very high precision. And most of the object does not require additional finishing

Disadvantages of Laser Beam Machining:

High initial cost. This is because it requires many accessories that are important to the machining process by Laser.
Laser beam machining requires a highly trained worker to operate the machine.
Low production rate since it is not designed for the mass production.
It requires a lot of energy for machining process.
It is not easy to produce deep cuts with the w/p that has high melting points and usually cause a taper.
High maintenance cost.

Application of Laser Beam Machining:

LBM lends itself for a wide range of applications in fields such as aerospace, automotive, electronic, nuclear sector, civil structures, and household. Advance high strength steels find application in boiler work and car industry and are machined using the LBM(Laser Bean Machining

The laser beam machining is mostly used in automobile, aerospace, shipbuilding, electronics, steel and medical industries for machining complex parts with precision.
In heavy manufacturing industries, it is used or drilling and cladding, seam and spot welding among others.
In light manufacturing industries, it is used for engraving and drilling other metals.
In the electronic industry, it is used for skiving (to join two ends) of circuits and wire stripping.
In medical industry, it is used for hair removal and cosmetic surgery.

So, here I discussed complete details of Laser Beam Machining -like,The Basic Elements Of Laser Beam machining (LBM),Advantages of Laser Beam Machining,Disadvantages of Laser Beam Machining,machine operation as well as also discussed in Working Principle of Laser Beam Machining.

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