-- the manufacturer of the equipment such as electron of equipment of the element of optical device electron that short pulse laser can have accurate helix shape bore is used at stiletto, medical treatment, sensor, computer, aviation needs a few parts, they have miniature measure, complex external form and alveolus appearance. The atomizer of the spinning jet that textile industry uses and train diesel engine is such example, these two example are metallic spare parts, above got careful alveolus. These typical alveolus size are M of μ of 50 - 100, alveolus deepness amounts to 2 Mm. With line cut discharge is machined, chemistry etchs, machining / cut, electroform, compare with photograph of etc processing technique, the function of laser stiletto equipment is close friends, because,this is of contact of dispute of laser beam machining, and more agile. In addition, the restriction that treatment process place accepts is fewer, do not need to undertake costly litter is handled, the cost of the tool is more reasonable also. Machine photograph comparing with discharge, laser stiletto can get taller length diameter is compared, in addition, it can undertake stiletto to all sorts of material, include pottery and porcelain, silicon, diamond and polymer. Because used agile laser light beam to scan, be not a circle even and the alveolus that has complex appearance can get. Creating the field of the hole with very small size, had had a series of blame contacts, ability that does not have attrition the alveolus art of 60 ì M, they used the beam of light of close together focusing, these technologies had built stated position in the production of microelectronics workmanship and engine spare parts. If alveolus must be round taper, will encounter special difficulty, because be on stiletto direction,the diameter is increasing ceaselessly. Appearance of this kind of geometry is need in a few spare partses, for instance nozzle component, they from cannot achieve reversely. Research center of Fraunhofer laser technology (ILT) the scientist had developed such stiletto technology, used the optical device of a kind of new-style accurate stiletto, it can offer very high scanning rate, and the alveolus geometry accuracy rate that can get is higher. Use laser radiate comes stiletto has been in all sorts of industry application already establish its position. Laser technology begins his to apply above all from watch industry. Get below energy-saving condition when need profound wide when compared alveolus, make medium cooling alveolus in aeriform turbine for instance, perhaps furnish in fuel the filter in the system, used laser, it already made a common tool. In these application, applied arteries and veins is wide the bore rate that the odd pulse that is a few small seconds has laser bore perhaps pounds bore to be able to get is higher. But because laser beam machining basically is heat process, laser bore brings about the remain inside aperture to have fused layer. By the laser of high strenth pulse is fused or the material of vaporization is being conveyed to go out by his vapour previously, can condense on hole wall or recast. More such in percussion drill aperture, here stimulates beam of light to did not move, always hit in same a place, the fused volume that this causes a generation is very large. Shorter pulse (level is measured in flying second and leather second) the heat that produces permeates deepness more shallow, still can remain however fused layer. But, when using this kind of laser, productivity is very low, because in pulse energy high case falls,this is, laser power is insufficient. Use call screw type stiletto / the limitation that punchs the stiletto technology of the law can overcome these quality and productivity respect. In this technology, the short pulse that used close together focusing stimulates beam of light, rotate along center, depict the geometrical exterior that gives alveolus strictly. In stiletto process, each fraction material is consecutive be evaporated, limits demarcate gets very good laser pulse to be rotated to be used with jackknife. When using this stiletto technology, in whole stiletto process, hole wall is heated all the time, this prevented the generation of thick layer of new and caky process and white. Used this technology, be in even of accept second limits " long " pulse also can be used, make thereby of more material evaporate to become a possibility with taller productivity, the result that can get ability gets use leather second pulse. The optical device of screw type stiletto depends on stimulate beam of light but focusing sex, it can be the circular alveolus that a diameter hits to amount to 30 micron on the material of 1mm in ply. Nextpage to undertake screw type stiletto, the optical device of special stiletto can with alterable whirl the diameter undertakes gyral to laser light beam. Already obtained a few progress to use implementation to stimulate the high accuracy that beam of light rotates in the past, they used traditional Zhenjing scanner, rotate wedge prism, and rotate from the axis lens. All these equipment need quality of tall beam of light, when asking laser light beam is rotational absolutely semmetry. If be ellipse model stimulate beam of light to there perhaps is other deviation on appearance, the alveolus that produces out of round. In addition, the maximum of the scanning frequency of these equipment is 3000 turn / minute. In this scanning frequency falls, of hole wall heat continuously cannot get assuring, perhaps say, in laser tall repeat the meeting below frequency to produce overheat phenomenon. Alveolus sample to overcome this problem, research center of Fraunhofer laser technology developed a kind of new-style laser stiletto head. Beam of light rotates prism, namely so called path power prism is used to the whirl that realizes laser light beam, it is gone to by installation on electromotor of high speed of drive of a hollow axis. Stimulate beam of light by adjust strictly, aim the center of path power prism, should rotate prism when, laser rotates twice. If opposite Yu Xuan turns,the axis tilts laser light beam, after passing focusing lens, the depict on the direction that beam of light will rotate in laser light beam gives a circle. In light beam of laser of the shift on as parallel as runner shaft coming back direction, laser light beam will come with certain an angle of incidence depict circle. Shuang Zhui rotate development of beam of light arrives data is inside relatively in, resemble a flight of stairs of screw type, become wider in bottom. It is OK that geometrical form also brings about laser light beam with electromotor along axial the speed of double rotates, reach every second 660 times / every second. This was compensated fluctuate to what luminous intensity stimulates when the surface when radiate of beam of light, got the alveolus with very high quality. Use this technology, can get conic alveolus (losing cone angle all but) . Use only adjust equipment technically, just may use path power prism to rotate as beam of light implement with scanning equipment, should adjust it is OK that equipment is installed together with path power prism compensation beam of light rotates implement typical error, cause the error of alveolus out of round namely. The bore optics device of new development makes the whirl of laser light beam frequency can be achieved 40, 000 turn / minute. The diameter can be hit to compare the cone-shaped alveolus that is as high as 2 on the material with thick 2-mm. The main advantage of new-style and optical device is scanning frequency very tall, do not rotate with all equipment that will install diameter and dip of laser light beam, in addition, they want to be able to offer very tall precision only when building can. Point of entry of screw type stiletto uses this one optical device and the Nd:Y that move QAG laser (arteries and veins is wide 15 accept second, pulse energy 600 to 800 μ J) , the researcher of technical research center machined Fraunhofer laser to have the tool steel with 2 thick millimeter and advanced course steel. Be in little inside the time at 25 seconds, pulse stimulates thin plate of smooth penetrable metal, hit a diameter to be the alveolus of 50 micron. The fused layer ply that remains in alveolus is only M of 1-2 μ , material coping melt can be cleaned through ultrasonic conveniently purify. It is into travel diameter limits on metallic component when the high accuracy stiletto inside a few micron use short pulse normally, perhaps exceed short pulse laser. Use this new-style laser stiletto head, can use accept second laser, this makes when manufacturing cost is inferior, productivity can taller. The pulse that uses shorter wavelengh (green is ultraviolet perhaps) can get smaller facula size, on the material that picks in a few classics, alveolus diameter can achieve M of 10-20 μ . So far, examined the tool steel that ply amounts to 2 Mm and advanced steel. Want to receive these geometrical form, realize precision requirement again, come true to a large number of expenditure ability must be being spent for traditional stiletto. In these respects, this one technology searched potential applied field. Arnold Gillner (Arnold. Gillner@ilt.
Fraunhofer.
De) serve with Welf Wawers at research center of Fraunhofer laser technology (Aachen, germany) , network address Www.
Ilt.
Fraunhofer.
De. CNC Milling
CNC Machining