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Laser and it’s applications.
(Laser welding)
The laser beam provides a variety of ways to join metals. It can join workpieces at the
surface or produce deep welds. It can be combined with conventional welding methods
and can also be used for soldering.
The laser beam welding is mainly used for joining components that need to be joined
with high welding speeds, thin and small weld seams and low thermal distortion. The
high welding speeds, an excellent automatic operation and the possibility to control the
quality during the process make the laser welding a common joining method in the
modern industrial production.
The application range covers finest welding of non-porous seams in medical technology
to precision spot welding in electronics or the jewelry industry, to deposit welding in
tool and mold-making and welding complete car bodies in automobile construction.
Since a laser beam can be controlled and located much more precisely than an arc or a
flame, the intense heat generated by its absorption in various materials is used for high
precision welding, drilling, and micromachining. No distortion is caused in the material
welded by laser because it produces minimum shrinkage. Traditional welding has its
limitations; certain materials cannot be welded by the conventional means. Laser technology has enabled reliable welding of gold with silicon and germanium, aluminium
with nickel, tantalum with copper and several other metals used in electronic equipment. With laser, it even possible to join metallic and non-metallic material.
Introduction of microcircuits into electronic equipment and thin film technology necessitated reliable spot welding like microwelding used in microelectronic circuits and
watch parts. In such cases where heat-affected zone is minimum and welds of microsize
are required, spot welding of high quality can be achieved by lasers without causing any
damage to the delicate metals and ceramics being welded. Successful laser welding of
high strength alloy steels, carbon-rimmed steel, tin-plated mild steel, etc has been
achieved 2-5 kW continuous wave carbon dioxide laser.
So, new and efficient production processes are often not possible without the advantages of laser technology.
Advantages
 Works with high alloy metals without difficulty
 Can be used in open air
 Can be transmitted over long distances with a minimal loss of power
 Narrow heat affected zone
 Low total thermal input
 Welds dissimilar metals
 No filler metals necessary
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 No secondary finishing necessary
 Extremely accurate
 Produces deep and narrow welds
 Low distortion in welds
 High quality welds
 Can weld small, thin components
 No contact with materials
Limitations
 Rapid cooling rate may cause cracking in some metals
 High capital cost for equipment
 Optical surfaces of the laser are easily damaged
 High maintenance costs (2805)
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