Laser cutting
group 3
members
yohanes bayu B-34
andreas henry S B-37
antonia karima B-38
doni heilyn B-40
Laser cutting is a technology that uses a laser to cut materials.
Laser cutting works by directing the output of a high-power laser,
by computer, at the material to be cut. The material then either
melts, burns, vaporizes away, or is blown away by a jet of gas,
leaving an edge with a high-quality surface finish. Industrial laser
cutters are used to cut flat-sheet material as well as structural
and piping materials.
Advantages of laser cutting over mechanical cutting include
easier workholding and reduced contamination of workpiece
(since there is no cutting edge which can become contaminated
by the material or contaminate the material). Precision may be
better, since the laser beam does not wear during the process.
There is also a reduced chance of warping the material that is
being cut, as laser systems have a small heat-affected zone.
Some materials are also very difficult or impossible to cut by
more traditional means.
Laser cutting for metals has the advantages over plasma
cutting of being more precise and using less energy when
cutting sheet metal, however, most industrial lasers cannot
cut through the greater metal thickness that plasma can. Newer
lasers machines operating at higher power (6000 watts, as
contrasted with early laser cutting machines' 1500 watt
ratings) are approaching plasma machines in their ability to
cut through thick materials, but the capital cost of such
machines is much higher than that of plasma cutting machines
capable of cutting thick materials like steel plate.
The main disadvantage of laser cutting is the high power
consumption. Industrial laser efficiency may range from 5% to 15%.
The power consumption and efficiency of any particular laser will
vary depending on output power and operating parameters. This will
depend on type of laser and how well the laser is matched to the
work at hand. The amount of laser cutting power required, known as
heat input, for a particular job depends on the material type,
thickness, process (reactive/inert) used, and desired cutting rate
process
Generation of the laser beam involves stimulating a lasing material
by electrical discharges or lamps within a closed container. As the
lasing material is stimulated, the beam is reflected internally by
means of a partial mirror, until it achieves sufficient energy to
escape as a stream of monochromatic coherent light. Mirrors or fiber
optics are typically used to direct the coherent light to a lens,
which focuses the light at the work zone. The narrowest part of the
focused beam is generally less than 0.0125 in (0.3175 mm). in
diameter. Depending upon material thickness, kerf widths as small as
0.004 in (0.1016 mm) are possible.[4] In order to be able to start
cutting from somewhere else than the edge, a pierce is done before
every cut. Piercing usually involves a high-power pulsed laser beam
which slowly (taking around 5–15 seconds for 1⁄2-inch-thick (13 mm)
stainless steel, for example) makes a hole in the material.
There are many different methods in cutting using lasers, with
different types used to cut different material. Some of the methods
are vaporization, melt and blow, melt blow and burn, thermal stress
cracking, scribing, cold cutting and burning stabilized laser
cutting.
