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LASER BEAM
WELDING
RISHIKESH V MISHAL
1602
TYME
8097927641
LASER BEAM WELDING
PRINCIPLE

Laser beam welding (LBW) is a welding technique used to join multiple pieces of
metal through the use of a laser. The beam provides a concentrated heat source,
allowing for narrow, deep welds and high welding rates.
SET UP FOR ‘LBW’

Laser beam equipment consists of a cylindrical ruby crystal with both the ends made
absolutely parallel to each other. Ruby is aluminum oxide (AlO2) with chromium
dispersed throughout it.

One of the end faces of the ruby crystal
highly silvered so that it reflects nearly
96% of the incident light. In order to tap
the laser output, the other end face of
the crystal is partially silvered and
contains a small hole through which the
laser beam emerges.

The ruby crystal is surrounded by a
helical flash tube containing inert gas
‘xenon’ which itself in turn is
surrounded by a ‘reflector’ to maximize
the intensity of the incident light on the ruby crystal. The flash tube converts
electrical energy into light energy.

Cooling system, either gas or liquid is provided to protect the ruby crystal from the
enormous amount of heat generated.

When the flash tube is connected to a pulsed high voltage source, xenon transforms
the electrical energy into while light flashes (light energy).

As the ruby is exposed to the intense light flashes, the chromium atoms of the
crystal are excited and pumped to a high energy level. These chromium atoms
immediately drop to an intermediate energy level with the evolution of discrete
quantity of radiation in the form of red fluorescent light.

As the red light emitted by one excited atom hits another excited atom, the second
atom gives off red light which is in phase with the colliding red light wave. The
effect is enhanced as the silvered ends of the ruby crystal cause the red light to
reflect back and forth along the length of the crystal.

The chain reaction collisions between the red light wave and the chromium atoms
becomes so numerous that, finally the total energy bursts and escapes through the
tiny hole as a ‘LASER BEAM’.

The laser beam is focused by an optical focusing lens on to the spot to be welded.
Optical energy as it impacts the workpiece is converted into heat energy.

Due to the heat generated, the material melts over a tiny area and upon cooling, the
material within becomes homogeneous solid structure to make a stronger joint.
APPLICATIONS

Laser is a high energy light beam that can both weld and cut the metals.

For connecting leads on small electronic components and in integrated circuitry in
the electronic industry.

To weld lead wires having polyurethane insulation without removing the insulation.
The laser evaporates the insulation and completes the weld.

To join hard high melting point metal alloys.

In space and aircraft industry for welding light gauge materials.
MANUFACTURERS

INDIANA GRATINGS PVT LTD (Indiana House, PB No 7409 Makwana Road Marol
Naka Mumbai).

RAJYOG FIRE SERVICES PVT LTD (C - 502, Steel Chambers 58, Devji Ratanshi Marg
Masjid Bunder East Mumbai).

EVEREST HOLOVISIONS LIMITED (201, Vardhaman Market Sector 17 Navi
Mumbai).

FORTRAN STEEL PVT LTD (A-111, Satyam Shopping Centre Mahatma Gandhi Road
Mumbai).

SHREE VAISHNAV INDUSTRIES PVT LTD (104 Shiv Ashish Complex 19th Road
Mumbai).