characteristics of drill EDM-laser drilling
Laser drilling is the first up to the drill edm to the practical use of laser processing technology, but also one of the main fields of application of laser processing. With the rapid development of modern industry and science and technology, high hardness, high melting point materials more and more, traditional processing methods can not meet the process requirements.
The high melting point metal molybdenum on-board processing of micron aperture; processing tens of microns holes in the hard tungsten carbide; red, sapphire processing hundreds of microns deep hole and diamond wire drawing dies, chemical fiber spinning top . This type of processing task using conventional machining methods very difficult, sometimes impossible, laser drilling is not difficult to achieve. The laser beam is highly concentrated in space and time, the use of the lens focus spot diameter can be reduced to the micron level in order to obtain 105-1015W/cm2 laser power density. Such a high power density can be almost any material to the implementation of laser drilling, and compared with other methods such as mechanical drilling, EDM, conventional punch means, with the following significant advantages:
1, the laser drilling speed, high efficiency, good economic returns.
Laser drilling is the use of instantaneous power density of the material for the high-energy laser beam l07-109W/cm2 reaction time of only 10-3-10-5s, laser drilling speed is very fast. High-performance lasers and high-precision machine tool and control system with microprocessor process control, can achieve high efficiency punch. Compared in the different laser drilling workpiece with EDM drilling and mechanical drilling, the efficiency of l0-1000-fold.
2, the availability of a large laser drilling depth to diameter ratio.
In the small hole machining, the depth to diameter ratio is a measure of the holes of the difficulty of processing - an important indicator. Is perforated with a laser beam, the laser beam parameters than the other punch grass easy optimization, so available to much larger than the EDM drilling and mechanical drilling depth to diameter ratio. Under normal circumstances, obtained by mechanical drilling and EDM punch depth to diameter ratio of not more than 10.
3, laser drilling in hard, brittle, soft, and other types of material.
High-energy laser beam punching mechanical performance limitations of the non-material hardness, rigidity, strength and fragility, both suitable for metallic materials, but also suitable for non-metallic materials is generally difficult processing, such as ruby, sapphire, ceramics, synthetic diamond and natural diamond. Difficult to machine materials mostly have high strength, high hardness, low thermal conductivity, processing and easy hardening, chemical affinity and other properties, cutting resistance, high temperature, short tool life, poor surface roughness, tilted surface to play Kong and other factors make drilling more difficult. Shock - the light in this
More difficult to machine materials, drilling, the above problem will be solved. Jewel bearings used by the watch industry in China almost all the laser drilling. Laser drilling applications of synthetic diamond and natural diamond is also very common. YAG laser thickness of 5 5mm carbide punch, depth to diameter ratio of up to l4: 1, in the 1l. 5mm thick of 65Mn depth to diameter ratio of l9: 1 small hole can be played on. L0mm thick hard silicon nitride ceramics can be easily played a diameter of 6mm holes, this is the conventional punch means can not be done. Especially in the elastic material, elastic material deformation, it is difficult to use the general method of drilling.
4, laser drilling tool wear and tear.
Laser drilling of non-contact processing, to avoid mechanical drilling porous brittle bit. Drilling machining diameter of 0. 8mm below the holes, even in the aluminum such a soft material, often fractured drill, which not only caused by tool wear and tear increase the cost, but also because of the drill breaks caused the entire workpiece scrapped. If the processing of the group orifice appears broken drill bit, make the problem more serious. In this case, the best way to remove the broken drill bit is still the laser drilling. Of course, the laser drilling equipment must have a sophisticated aiming device, in order to accurately knock down the broken drill bit.
In addition, because the laser drilling process does not contact with the workpiece, the processing out of the workpiece clean, no pollution. Because this punch is an evaporation-type non-contact process, which eliminates the conventional hot-wire perforation and mechanical perforation residue, which is very health. And laser processing time is short, raw materials, oxidation, deformation, heat affected zone are small, does not require special column protection. The laser can not only the workpiece punch in the air, but also punch the workpiece in a vacuum or under other conditions. Thus, the laser is an effective tool for a high-quality, fast punch.
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