G.Weike Laser
Profession Laser Manufacturer more than 15 Years.
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4).With the work-piece or cutting head movement, small transverse and cut
into a seam, continue along the seam at the forefront of laser beam irradiation,
the melt material in continuous or pulse from the seam was blown off.
For sheet material, cutting speed too slow will make the most of the laser
beam directly through incision throw energy, speed increase more beam material,
increase the coupling power and material, to obtain wider parameter adjustment
to ensure the quality of cutting area, to the thick plate material, due to the laser
evaporation or melt products cannot move fast enough, beam on the material
aspect in the slot many reflect, as long as melt producer before remove were
cool air, cutting process will keep.
All laser cutting edges are striped, its reason is:
①.
Cutting process started in the cause of oxygen combustion power value,
and stop at lower power levels;
②
.Cutting section is so steep that the power density on it cannotcontinue
to maintain the melting process, and the cut surface forming steps, make the cut
surface in the process of cutting intermittently forward;
③.
Cutting reflect or absorb plasma or smoke can cause intermittent effect.
laser oxygen cutting principle is similar to the oxyacetylene cutting, it is to use
laser as a heating source, with oxygen reactive gas as cutting gas. on the one
hand ,out of gas and metal effect, oxidation reaction, release a large amount of
heat oxidation; On the other hand the molten oxide and melt blown out from
the reaction zone, form the incision in the metal. The brief analysis of as
following:
1) Under laser irradiation, the surface of material is heated to the ignition
temperature, then it acted with oxygen, acting Violent oxidation
reaction, releasing quantity of heat. Under the influence of the heat,
t h e inside of the material formed holes with steam. Around the
holes is surrounded by the melting metal-wall.
2) The flowing of the steam makes the melting metal-wall move forward
and the occur heat and mass transfer.
3) The rate of oxidation about oxygen and metal is controlled byOxidation
mass transferring into molten slag, and also the speed of the oxygen
through molten slag to reach the ignition front.
4) The speed of flowing oxygen faster, the speed of the burning reaction
and wiping off material higher. Meanwhile, also contributing the
reaction product of the slit outlet -rapid cooling oxide.
5) Obviously, the two heat source of oxygen to help cut: laser energy and
oxygen-metal exothermic reaction, a rough estimate, cutting carbon
steel, oxidation reaction to provide energy for about 60% of all cutting
energy, obviously, compared with an inert gas, auxiliary gas oxygen do
high speed can be obtained.
6) Oxygen combustion rate is higher than the beam speed when the slot
width and coarse: laser beam speed is greater than the oxygen
combustion rate, narrow kerf width, smooth, faster, mutate to cut.
7) Because of oxidation reaction heat of large role, the purity of
