The innovation that an ultrashort pulsed laser can bring to manufacturing is discussed next from the perspective of unique control over. In this publication the influence of the type of intensity distribution neargaussian, tophat, of its geometry circular, square. A new generation of lasers called fiber lasers also have similar wavelength where the laser light is produced in the fiber itself. A fundamental study of pulsed laser micro polishing plp was conducted as a method for reducing surface roughness of micromesoscale metallic parts. P was conducted as a method for reducing surface roughness of micromesoscale metallic parts. P with pulse durations of 300650 ns and a spot size of 60. In recent years, laser polishing has been widely used in the field of material surface processing.
In this paper, we have investigated a method which controls the energy density of ultraviolet uv pulse laser in real time with the control of continuous wave cw laser spot size in laser micropolishing for metallic surface. P as oscillations of capillary waves with damping resulting from the forces of surface tension and viscosity. P has been shown to be an effective method of polishing micro metallic pa rts whose surface roughness can approach the feature size. Laser micropolishing for metallic surface using uv nano.
Influence of intensity distribution and pulse duration on. Effects of laser pulse duration on pulse laser micro polishing. Effects of pulse duration on laser micro polishing journal. Pulsed laser micro polishing pl p is a non contact surface finishing process that uses pulses of laser irradiation to melt the surface of a m etallic substrate and achieve subsequent.
Laser polishing, fiber optics, pulsed laser, fiber injection, fiber threshold, optical damage. Influence of laser spot scanning speed on micro polishing. P with pulse durations of 300650 ns and a spot size of 60 m is a method by which the surface roughness of microfabricated and micro milled parts can be effectively reduced. Laser polishing of metals process variants macro polishing micro polishing laser radiation continuous wave cw pulsed 100 ns schematic drawing remelting depth 20 100 m laser beam source continuous wave or pulsed optional. Prospects of laser polishing for small and complexly shaped parts. Smoother surfaces with pulsed laser polishing inventors frank pfefferkorn, xiaochun li, neil duffie, chao ma, venkata madhukanth vadali since its founding in 1925 as the patenting and licensing organization for the university of wisconsinmadison, warf has been working with business and industry to transform university research into products.
Irregular, adaptive scan trajectories for pulsed laser micro. Formation mechanism of a smooth, defectfree surface of fused. Micro and nano structuring with ultra short pulsed lasers for. Tactile probe for determination of part orientation, process gas system with more than one inert gas. The goal of this work, therefore was to improve upon the existing knowledge of pl. Sep 14, 2011 this project is focused on developing physics based models to predict the outcome of pulsed laser micro polishing pl. Usually, laser ablation refers to removing material with a pulsed laser, but.
May 15, 2017 introduction pulsed laser micro polishing pl. During polishing the properties of the laser radiation have a great influence on the results. Preheating laser power, scanning velocity, beam offset of the two laser beams, and intensity distribution of the preheating laser beam. Laser polishing of metals fraunhofer institute for laser technology ilt dqs certified by din en iso 9001 reg. Although plp was shown to be an effective process at these scales, the knowledge of the process physics lacked thoroughness. At high laser flux, the material is typically converted to a plasma. Customerspecific requests can, therefore, easily be accommodated. Dissertation, university of wisconsinmadison usa influence of intensity distribution and pulse. Pulsedlaser machining and polishing of silica micro. Abstract in this publication laser micro polishing with an additional laser beam for preheating of the surface is investigated.
Pdf pulsed laser micro polishing of metals using dual. Tool steel has been widely used for injection molding and diecasting applications, as well as functional components. At low laser flux, the material is heated by the absorbed laser energy and evaporates or sublimates. The innovation that an ultrashort pulsed laser can bring to manufacturing is discussed. For micro laser polishing pulsed laser radiation is used, which is a combination of remelting a thin surface layer smaller than 5 m and vaporization of micro edges fig ure 1 b 1289. The target is ablated to form a plume of atoms, molecules and chunks. P is a noncontact surface smoothing process suitable for metallic parts of micro meso scales, where conventional polishing methods are unproductive andor uneconomic. The influence of the following process parameters on the surface roughness is examined. Qian lin, xing fu, and feng lie zhang design of pulse laser micropolishing system, proc. Pulsed laser micro polishing engineers world online. All of our plds are developed and manufactured at our laser components production facility in canada. Pulsed laser micro polishing of metals using dualbeam technology. Another method of achieving pulsed laser operation is to pump the laser material with a source that is itself pulsed, either through electronic charging in the case of flash lamps, or another laser which is already pulsed. Synergetic effect of laser patterning and micro coining for.
Pulsed laser micro polishing of metals using dualbeam technology phys. Effects of pulsed laser micro polishing on microstructure. Pulsed laser ranging techniques based on digital signal processing methods. Laser ablation and laser smoothing of silica is investigated as a method of manufacturing custom micro optics for use with highpower, diode laser arrays.
Improved surface finish and smoothness can be achieved on select areas of different metallic surfaces, produced by mesomicro. Laser polishing could be very suitable for tool steel workpieces made by additive manufacturing am techniques since these manufactured objects usually have poor surface quality that cannot meet the smooth surface requirements and tight geometric tolerances. P was shown to be an effective process at these scales, the knowledge of the process physics lacked thoroughness. Besides, the cracks on pristine fused silica surfaces introduced by initial grinding process were completely removed by laser polishing to achieve a defectfree surface. The laser micro polishing experiments had been carried out for the ti and ni metal surfaces. Curriculum vitae chao ma tamu college of engineering. P, laser pulses irradiate the surface, and each pulse results in melting of the surface asperities in a small area. Polishing fraunhofer institute for laser technology ilt.
Pulsed laser micro polishing of metals using dualbeam technology article pdf available in physics procedia 41. In this paper, during micropolishing on the metallic surface by using uv nanosecond pulse laser, the influence of laser spot. A highly flexible machining regime has been identified that uses 30 to 60 microseconds square pulses, generated from a stabilized co 2 laser by an acoustooptical modulator aom. During laser micro polishing of the metallic surface, it is very important to choose the optimal laser energy density and laser spot scanning speed. Range of materials laser polishing is particularly well suited for nickel, titanium and cobaltchromium alloys. A new generation of lasers called fiber lasers also have similar wavelength where. Furthermore, the fraunhofer ilt is engaged in laser plant. During laser micropolishing, the controllable laser energy density is a key technology to improve the surface roughness.
Results from recently build fibers will be shown to demonstrate the techniques. Studies show that in the polishing process, the laser energy directly affects the effectiveness and efficiency, and usually when the incident laser energy is determined, the laser fluence on the material surface can be characterized by the laser spot area. Recent citations surface topography following pulsed laser texturing. In this contribution, we expand these all laser based approaches by differently employing the ultrashort pulsed laser for geometry definition and sole co 2 a defocussed laser for subsequent sole polishing we exemplify the p. Melt pool flow and surface evolution during pulsed laser micro polishing of ti6al4v c ma, m vadali, na duffie, fe pfefferkorn, x li journal of manufacturing science and engineering 5 6, 061023, 20. P has been shown to be an effective method of polishing micro metallic parts whose surface roughness can approach the feature size. Pulsed laser diodes plds are available in the wavelengths 850 nm, 905 nm and 1550 nm. P process is an important parameter that significantly affects the achievable surface finish. Laser polishing of ground aluminum surfaces with high energy. Yag wavelength that has the option of being transmitted through an optical fiber.
This project is focused on developing physicsbased models to predict the outcome of pulsed laser micro polishing pl p. Pdf pulsed laser micro polishing metals using dual beam. Laser polishing and laser shape correction of optical glass christian weingarten,a andreas schmickler, edgar willenborg. Fabrication of cylindrical lenses by combining ultrashort. Laser polishing of additive manufactured tool steel. Effects of pulse duration on laser micro polishing. Laser micro polishing with pulsed laser radiation is a process to reduce the micro roughness of surfaces. Pulsed laser micro polishing of metals using dualbeam.
Laser ablation and laser smoothing of silica is investigated as a method of manufacturing custom microoptics for use with highpower, diode laser arrays. Laser ablation or photoablation is the process of removing material from a solid or occasionally liquid surface by irradiating it with a laser beam. Pulsedlaser machining and polishing of silica microoptical. Excimer laser mirror lens yba 2cu 3o 7x target substrate plume faceplate pulsed laser ablation a highpower excimer laser is focused on the target. Surface prediction model the objective of this work is to predict the final roughness of metal surfaces that have undergone pulsed laser micro polishing. This paper will describe the influence of laser pulse duration on surface roughness reduction during pl. Irregular, adaptive scan trajectories for pulsed laser.
And the laser energy density for obtaining the optimum micro polishing effect is also related to the scanning speed of the laser spot. Motivation laser micro polishing with pulsed laser radiation is a surface finishing process to reduce the micro roughness. Improved surface finish and smoothness can be achieved on select areas of different metallic. The advantage of pld is that complex materials can be easily ablated. Surface evolution during pulsed laser micro polishing of ti6al4v. Aug 19, 2011 in recent years, laser polishing has been widely used in the field of material surface processing. Publications by members of the tribology and nonlinear dynamics laboratory. Effects of pulsed laser micro polishing on microstructure and. A numerical and experimental study of pulsed laser polishing of metals at the meso micro scale. Laser polishing and laser shape correction of optical glass christian weingarten,a andreas schmickler, edgar willenborg, and konrad wissenbach fraunhofer institute for laser technology ilt, steinbachstr 15, d52074 aachen, germany. Improved surface finish and smoothness can be achieved on select areas of different metallic surfaces, produced by meso micro. The asme international manufacturing science and engineering conference, madison, wi, us. This project is focused on developing physics based models to predict the outcome of pulsed laser micro polishing pl. In this paper, we have investigated a method which controls the energy density of ultraviolet uv pulse laser in real time with the control of continuous wave cw laser spot size in laser micro polishing for metallic surface.