Laser drilling is the earliest practical laser processing technology, and it is also one of the main application areas of laser processing. With the rapid development of modern industry, more and more materials with high hardness and high melting point are used, and traditional processing methods can no longer meet certain process requirements. The laser beam is highly concentrated in space and time. Using a lens to focus, the spot diameter can be reduced to micrometers. Such a high power density can be used to perform laser drilling on almost any material, and compared with other methods such as mechanical drilling, EDM and other conventional drilling methods, it has the following significant advantages:
(1) Laser drilling is fast, efficient and economical.
Since laser drilling uses a high-energy laser beam to instantaneously act on the material, the action time is only a few seconds, so the laser drilling speed is very fast. Cooperating with high-efficiency lasers and high-precision machine tools and control systems, through the microprocessor for program control, high efficiency drilling can be achieved.
(2) Large depth-diameter ratio can be obtained by laser drilling.
In the processing of small holes, the ratio of depth to diameter is an important index to measure the difficulty of processing small holes. With laser beam drilling, the laser beam parameters have a greater depth to diameter ratio than electric spark drilling and mechanical drilling.
(3) Laser drilling can be performed on various materials such as hard, brittle, and soft.
High-energy laser beam drilling is not limited by the hardness, rigidity, strength and brittleness of the material. It is suitable for metal materials and non-metallic materials that are generally difficult to process, such as ruby, sapphire, ceramic, synthetic diamond and natural diamond etc. Since most difficult-to-process materials have the properties of high strength, high hardness, low thermal conductivity, easy hardening during processing, and strong chemical affinity. Therefore, due to the high resistance, high temperature, short tool life, poor surface roughness, and drilling on inclined surfaces in the cutting process, it is more difficult to punch. The above problems will be solved by using laser to drill holes in these difficult-to-process materials.
(4) Laser drilling has no tool loss.
Laser drilling is a non-contact processing, which avoids the problem of easy breakage of the drill bit during mechanical drilling.
(5) Laser drilling is suitable for processing a large number of high-density group holes.
Because the laser drilling machine can cooperate with the automatic control system and the microcomputer to realize the integration of light, machine and electricity, the laser drilling process can be repeated thousands of times without error. Combining the characteristics of laser drilling with small aperture and large depth-to-diameter ratio, through program control, a small aperture, large number, and high density group orifice plate can be produced continuously and efficiently.
(6) Small holes can be processed on the inclined surface of difficult-to-process materials with laser.
For contact punching such as mechanical punching and electric spark punching, it is very difficult to punch holes on an inclined surface. The main problem of the small hole processing on the inclined surface is that the drill bit is difficult to drill. The cutting edge of the drill bit is single-edge cutting on the inclined plane, and the force on both sides is uneven, causing slippage and difficulty in drilling, and even the drill bit is broken. However, the laser can process small holes on the inclined surface of difficult-to-process materials.
In addition, because the laser drilling process does not touch the workpiece, the processed workpiece is clean and free from pollution. Moreover, the laser processing time is short, and the area of oxidation, deformation, and heat affected by the processed material is small, and no special protection is required. It can be seen that the laser is an effective tool for high-quality and fast drilling.