Laser Hole Cutting Technology
For any kind of thermal cutting technology, a small hole must be cut first in the sheet metal, except in a few cases, cutting starting from the edge. If it is not laser cutting punching compound machine, there are two basic ways of perforating generally.
The material forms a pit in the center after continuous laser irradiation, and then the molten material is quickly removed by the oxygen flow coaxial with the laser beam to form a hole. Generally, the size of the hole is related to the thickness of the plate. The average diameter of the blasting perforation is half of the thickness of the plate. Therefore, the blasting perforation of the thicker plate is large and not round, so it should not be used on more high precision parts (such as petroleum sieve tube ), Can only be used on waste material. In addition, because the oxygen pressure used for perforation is the same as that for cutting, there is a lot of splashes.
Pulse drilling uses a high peak power pulse laser to melt or vaporize a small amount of material. Air or nitrogen is often used as auxiliary gas to reduce the expansion of the hole due to exothermic oxidation. The gas pressure is lower than the oxygen pressure during cutting. Each pulsed laser produces only small jets of particles, stepping deeper, so thick plate perforation takes a few seconds. Once the perforation is complete, the auxiliary gas is replaced with oxygen for cutting. In this way, the diameter of the perforation is small, and the quality of the perforation is better than that of blast drilling. The laser used for this purpose should not only have a high output power but also suitable time and space characteristics.
In addition, pulse drilling also requires a more reliable gas path control system to achieve the switching of gas type, gas pressure, and perforation time.
