18-07-2016, 12:51 PM
Laser beam machining
Laser beam machining (LBM) is a non-traditional subtractive manufacturing process, a form of machining, in which a laser is directed towards the work piece for machining. This process uses thermal energy to remove material from metallic or nonmetallic surfaces. The laser is focused onto the surface to be worked and the thermal energy of the laser is transferred to the surface, heating and melting or vaporizing the material. Laser beam machining is best suited for brittle materials with low conductivity, but can be used on most materials.
Laser represents the full form of Light Amplification by Stimulated Emission of Radiation. The fundamental working principle of laser was invented by ALBERT EINSTEIN in 1917 through the first Industrial Laser for experimentation and was developed around 1960s. Laser beam can be easily focused using optical lenses as their wavelength ranges from half micron to around 70 microns. Focused laser beam can have power density in excess of 1 MW/mm^2.
Laser Beam Machining or we can broadly consider as processing deals with machining and material processing like heat treatment, alloying, cladding, sheet material bending etc. Such processing is carried out utilizing the energy of coherent photons or laser beam, which is almost converted into thermal energy upon interaction with most of the materials. As laser interacts, the energy of the photon gets absorbed by the work which results in rapid rise in temperature. This results in melting of the work material and finally material removal. Now a days, Laser beam machining is used in regenerative machining and rapid prototyping as in processes like stereo-lithography, selective laser sintering etc.
Laser beam machining
In this model of atom, all the negatively charged electrons rotate round the positively charged nucleus in some specified orbital paths. At absolute zero temperature, all the atoms are considered to be at ground level where all the available electrons occupy their respective lowest potential energy. These atoms when gets excited results in laser which in turn is very helpful for laser beam machining.
Many types of materials can be used as the heart of the laser which mainly depends on the lasing medium which again gets classified into solid state laser and gas state laser. Solid state lasers are commonly RUBY- Chromium alumina alloy, ND-Glass laser, ND-YAG laser which are generally used in material processing. Gas lasers are mainly of three types namely Helium-Neon, Argon, CO2. Laser machining can be done when the power density of the beam is much greater than the power lost by radiation, conduction and convection. The radiation must also penetrate and to be absorbed into the material.
PARAMETERS AFFECTING Laser beam machining
Working Material
Environment
Quality of Holes
Laser pulse types
Assist Gas
Focusing lens
ADVANTAGES
Tool wear and breakage are not encountered
Holes can be located accurately
Even very tiny holes can be produced
Machining is extremely rapid
Holes can also be drilled at difficult entrance angles
Operating cost is very low
Disadvantages
The equipment cost is very high
Tapers are normally encountered in direct drilling of holes
A blind hole of precise depth is very difficult to achieve with a laser
The thickness of material which has to be laser drilled is restricted to 50mm
Adherent materials has to be removed for sure
Applications
Cutting of materials, both soft and hard materials
Scribing of any material
Drilling of all substrates
Trimming all the hybrid resistors
Patterning displays of all glass and plastic wafers and chips
Laser beam machining (LBM) is a non-traditional subtractive manufacturing process, a form of machining, in which a laser is directed towards the work piece for machining. This process uses thermal energy to remove material from metallic or nonmetallic surfaces. The laser is focused onto the surface to be worked and the thermal energy of the laser is transferred to the surface, heating and melting or vaporizing the material. Laser beam machining is best suited for brittle materials with low conductivity, but can be used on most materials.
Laser represents the full form of Light Amplification by Stimulated Emission of Radiation. The fundamental working principle of laser was invented by ALBERT EINSTEIN in 1917 through the first Industrial Laser for experimentation and was developed around 1960s. Laser beam can be easily focused using optical lenses as their wavelength ranges from half micron to around 70 microns. Focused laser beam can have power density in excess of 1 MW/mm^2.
Laser Beam Machining or we can broadly consider as processing deals with machining and material processing like heat treatment, alloying, cladding, sheet material bending etc. Such processing is carried out utilizing the energy of coherent photons or laser beam, which is almost converted into thermal energy upon interaction with most of the materials. As laser interacts, the energy of the photon gets absorbed by the work which results in rapid rise in temperature. This results in melting of the work material and finally material removal. Now a days, Laser beam machining is used in regenerative machining and rapid prototyping as in processes like stereo-lithography, selective laser sintering etc.
Laser beam machining
In this model of atom, all the negatively charged electrons rotate round the positively charged nucleus in some specified orbital paths. At absolute zero temperature, all the atoms are considered to be at ground level where all the available electrons occupy their respective lowest potential energy. These atoms when gets excited results in laser which in turn is very helpful for laser beam machining.
Many types of materials can be used as the heart of the laser which mainly depends on the lasing medium which again gets classified into solid state laser and gas state laser. Solid state lasers are commonly RUBY- Chromium alumina alloy, ND-Glass laser, ND-YAG laser which are generally used in material processing. Gas lasers are mainly of three types namely Helium-Neon, Argon, CO2. Laser machining can be done when the power density of the beam is much greater than the power lost by radiation, conduction and convection. The radiation must also penetrate and to be absorbed into the material.
PARAMETERS AFFECTING Laser beam machining
Working Material
Environment
Quality of Holes
Laser pulse types
Assist Gas
Focusing lens
ADVANTAGES
Tool wear and breakage are not encountered
Holes can be located accurately
Even very tiny holes can be produced
Machining is extremely rapid
Holes can also be drilled at difficult entrance angles
Operating cost is very low
Disadvantages
The equipment cost is very high
Tapers are normally encountered in direct drilling of holes
A blind hole of precise depth is very difficult to achieve with a laser
The thickness of material which has to be laser drilled is restricted to 50mm
Adherent materials has to be removed for sure
Applications
Cutting of materials, both soft and hard materials
Scribing of any material
Drilling of all substrates
Trimming all the hybrid resistors
Patterning displays of all glass and plastic wafers and chips