2017年03月11日

Laser Cutting Machine Proofing

Nursing laser cleaning is divided into two categories: one is the stone and the appearance of the dust attached to a wavelength of laser energy absorption coefficient of different, so that the laser energy is fully absorbed by the dirt absorbed, and then by thermal expansion or vaporization evaporation, And vaporization of the composition of the vapor flow from the stone to achieve the purpose of cleaning. The other is the stone and the appearance of the attachment of the high powered laser pointer beam absorption coefficient is different from the laser beam is adjusted to a specific energy value, without destroying the stone surface, while the surface attachment can be high-power pulse laser shock stone surface , So that part of the beam into sound waves, sound waves in the impact of stone after the appearance of back, the return of some of the laser and the role of sound waves to form a resonance wave, so that a slight burst of crack, resulting in crushing, and thus from the stone appearance.

With laser welding and cutting process has been many years of history, but with laser cleaning stone surface is a relatively young technology. Although this process can remove all organic materials, but in the stone care process applications until recently began. I believe that with the development of laser and laser cleaning technology continues to improve, will be in a variety of cleaning areas get more and more applications.

The quality of laser cutting machine is mainly to see the quality of cutting, which is the most direct way to test the quality of equipment. For new customers, in the purchase of equipment will require look at the laser cutting machine proofing, proofing in addition to watching the cutting speed of the device, it is to look at the quality of cutting the sample. Laser cutting section will form a vertical pattern, the depth of the groove determines the roughness of the cutting surface, the more shallow the lines, the more smooth cutting section. Roughness not only affects the appearance of the edge, but also affect the friction characteristics, in most cases, the need to minimize the roughness, so the more shallow lines, the higher the quality of cutting. The verticality of the cutting edge is very important, away from the focus, the 1000mw green laser beam becomes divergent, depending on the position of the focus, the cutting is widened toward the top or bottom. The cutting edge deviates from the vertical line by a few millimeters, the more vertical the edge, the higher the cutting quality.

Cutting width. The width of the cut does not generally affect the quality of the cut, and the cut width has an important effect only when a particularly precise profile is formed inside the part, since the width of the cut determines the minimum internal meridian of the profile. The increase. So want to ensure the same high precision, no matter how much the width of the workpiece, the workpiece in the laser cutting machine processing area should be constant.

High-speed cutting thick plate, the molten metal does not appear in the vertical 3000mw laser pointer beam below the incision, but will be sprayed in the laser beam behind. As a result, the curved lines are formed at the cutting edge, and the lines follow the moving laser beam. To correct this problem, the feed rate is reduced at the end of the cutting process, and the behavior of the lines can be largely eliminated. The formation of the burrs determines a very important factor in the quality of the laser cutting, since the removal of the burrs requires additional effort, so the amount of burrs is serious and how much is able to visually determine the quality of the cutting.

The laser cutting machine first touches a special liquid with oil on the surface of the workpiece before it begins to melt and pierce. During the cutting process, due to gasification and the various materials are not used, the customer uses the wind to blow the cut, but the upward or downward discharge will also form deposition on the surface. Depression and corrosion. Depression and corrosion have an adverse effect on the surface of the cutting edge, affecting the appearance. They appear in the general should be avoided in the cutting error. Heat affected area. In 5000mw green laser cutting, the area is heated along the area near the incision. At the same time, the structure of the metal changes. For example, some metals will harden. The heat affected area refers to the depth of the area where the internal structure changes. If the cutting causes the part to drastically heat, it will deform. This is especially important in fine machining because the contours and connectors here are usually only a few millimeters wide. Control of laser power and the use of short laser pulses can reduce component heat and avoid deformation.

Laser cutting machine in the cutting process, the auxiliary gas is essential! Which we often use oxygen and nitrogen, of course, the higher the purity of the gas, the quality of cutting will be better. So, in order to achieve a better cutting effect, the requirements of the auxiliary gas is relatively high! Although the air can be used as auxiliary gas, but because the air contains water and oil, if not treated, will cause the lens pollution, cutting head instability, so that the cutting effect and quality is not compliance. Therefore, in the use of air cutting, the need for fiber burning laser pen cutting machine equipped with cold and dry machine, so that a very good solution to this problem. The cold and dry machine can be forced to cool the compressed air below the required dew point temperature, which will contain a large number of water vapor, oil mist condensed into droplets, separated by gas and liquid, discharged from the drainage machine, the compressed air drying.

http://eyes123456.inube.com/blog/5695208/high-power-single-longitudinal-mode/

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http://www.mamacommunity.de/mitglied/laserman123/blog/low-power-lasers-flexibly  
タグ :laser pointer


Posted by laserman at 19:13Comments(0)Technology

2017年03月03日

Artificial Electromagnetic Materials

Artificial electromagnetic materials are material materials that control light in an unusual way at nanoscale. They can be used to develop foreign equipment such as invisible cloaks to quantum computers. But the problem is that the metamaterials they use usually contain metals that absorb energy from light and convert it into heat. As a result, a portion of the optical signal is wasted, reducing the efficiency of the device. A photonics 500mw laser pointer research team led by Shaya Fainman, an electrical engineering professor at the University of California, San Diego, demonstrated the use of metallic materials that add excitation light to compensate for these optical losses, an optical semiconductor.

Laser cutting has the same advantages as conventional processing methods. In the thermal cutting method, oxygen-combustible (such as acetylene) cutting and plasma cutting can not concentrate as much energy as a laser beam in a very small area, resulting in large incision width, large heat affected area and more obvious deformation of the workpiece. Oxygen- combustible cutting equipment is small, less investment, can cut up to 1m thick steel plate, is a very flexible cutting tools, mainly used to cut low carbon steel. However, due to its large heat affected area, cutting speed is low, the incision appears serious jagged and corrugated. Therefore, it is rarely used to cut the thickness of 20mm or less and require accurate size of the material. Plasma cutting is similar to 400mw laser pointer cutting speed, significantly higher than acetylene flame cutting. But its cutting energy is low, trimming at the top of a round head, cut from the obvious waveform.

In operation, but also to prevent the arc generated by the UV radiation on the operator of the damage. Conventional fiber lasers use fiber-coupled technology to couple multiple laser outputs together, resulting in lower brightness of the output laser. The new generation of fiber lasers uses an innovative architecture that combines the pump diodes and drivers into separate pump modules. The gain fiber is mounted in a configurable gain module that can output more than 8kW of laser power. The gain module is based on the novel main oscillator / power amplifier (MOPA) design, enabling high-brightness 300mw laser pointer output. In addition, the Ennie laser also uses a reliable integrated backlash isolator to protect all modules from the impact of backlit light, can be high anti-material for full power, uninterrupted, stable processing. These two technological innovations play a vital role in RLS applications.

For iron and steel enterprises, the establishment of laser processing sheet metal distribution center, has a unique advantage. First, the production of sheet metal production and sales base, over the years to establish a wide range of sales channels, customer relations and sales network, the production and sales base of the plate, ; The small batch, multi -species needs of users, can directly provide the finished product after 10mw laser pointer precision processing to extend the service chain of the product, resulting in a secondary benefit; cutting waste can be quickly recycled; at the same time, reduce the intermediate transport links, Cost savings, to maximize the profits. And behind all this, laborers can provide long-term, strong technical support.

This is the first time with metal and semiconductor coexistence of a material. If light is one of the ways of polarization, the metamorphic light will be like metal, and when light is polarized in other ways, the metamaterial absorbs and emits light in different colors, like semiconductors, "says Smalley. The new metamaterials, first grown into a crystalline semiconductor material, are called indium gallium arsenide, are on the substrate. Then they use plasma blue laser pointer high-energy ion etching to narrow the grooves to achieve the semiconductors, create 40 nanometers wide and the line spacing of 40 nanometers.Finally, they use silver to create an alternate striped pattern and a silver nanocrystalline trench.

Laser cutting is a kind of high energy density controllable non-contact processing. It focuses the burning laser beam into a spot with a minimum diameter of less than 0.1mm, so that the power density at the focal point can exceed 107W to 108W / cm ~ 2. The irradiated material is quickly heated to the vaporization temperature and evaporated to form pores. As the beam moves relatively linearly with the material, the apertures are continuously formed with slits of about 0.1 mm in width. The cutting also adds auxiliary gas to the material to be cut to accelerate the melting of the material, blown away the slag or protecting the slits from being oxidized.  
タグ :laser pointer


Posted by laserman at 18:58Comments(0)Technology

2017年02月22日

Simulation Method of Analytical Laser 3D Printing Composites

In the strongest laser pointer processing environment, the metal melting process has more than 50 different factors play a role, after the National Institute of Standards and Technology - NIST plans to establish a weight production manufacturing test platform for the assessment of process measurement and control technology , Enabling them to observe the melting and solidification processes of metal powders, integrating process metering tools, and developing control algorithms and software for process measurement / testing based on data acquisition.

During the 3000mw green laser processing, the heat transfer process between the particles and the melt interface in the molten bath has an important effect on the motion behavior of the particles, which in turn affects the uniformity of the tissue. In particular, the material system, such as the non-equilibrium melting The pool will accelerate the floating or sinking of the particles; at the same time, the distribution of the enhanced particles also with the melt flow and liquid-solid front are closely linked.

The numerical simulation of the heat transfer and mass transfer between the particles and the melt interface is a complex research involving three-dimensional spatial and multi-physical fields. The previous research focuses on the temperature field and velocity field of the molten pool, including the melting interface of the powder, Interface and gas-liquid interface, but are basically not involved in the interaction between the melt and the enhanced particles, in particular the quantitative analysis of enhanced particles and melt heat transfer process. The metal melt adjacent to the reinforced particles has a large temperature gradient and a more pronounced dynamic viscosity, ie, there is a thermal boundary layer in fluid mechanics.

The enhanced particles in the burning laser pointer, the surface will melt and accompanied by element diffusion, and then the particles / melt interface near the formation of chemical composition gradient. Under the combined action of chemical composition gradient and temperature gradient, the rheological properties of the fluid at the particle / melt interface will be extremely complex and can only be solved by some empirical values ​​and imperfect mathematical models, which can not be quantitatively and dynamically Metallurgical behavior between particles and melt interface.

At the same time, laser processing with high temperature overheating melting powder and accompanied by the rapid cooling of the characteristics of the pool, the experimental observation is unrealistic. However, the distribution of the enhanced particles in the solidification matrix directly affects its service performance. The uniformly distributed reinforcing particles can effectively transmit and carry the load on the substrate and avoid early failure. At present, there is no project available in the laser processing process pool to enhance the particle and melt interface heat transfer mass transfer simulation software.

The mathematical model of the heat transfer and mass transfer between the particles and the melt interface during the green astronomy laser processing was simulated by computer. The simulation results show that the particle size of the particles can be dynamically and quantitatively The temperature field, velocity field and pressure field of the interface between the particle and the melt are studied, and the distribution of the particles in the solidification matrix is ​​predicted. The mapping relationship between the process and interface is established. The development of composite laser processing technology, to improve the distribution of particles in the matrix and get a uniform microstructure to provide theoretical guidance. Therefore, Nanjing University of Aeronautics and Astronautics has solved the problem of quantitative or semi-empirical deterministic model of laser processing, and realized the quantitative study on the heat transfer and mass transfer between the enhanced particle and the melt interface, and accurately predicted the enhancement of the particles in the solidification matrix Of the distribution of the state.

The micro - macro - scale multi - scale coupling simulation was carried out to enhance the heat brightest laser pointer transfer and mass transfer between the particles and the melt interface, and the relationship between the particle and the melt interface was discussed. That is, to enhance the movement of particles under the action of the melt mechanism and the final distribution in the solidified structure.

Based on the combination of numerical simulation, hydrodynamics and thermodynamics, the heat transfer and mass transfer processes between the particles and the melt interface were reconstructed at different scales and positions. The thermodynamic and kinetic mechanisms of the metallurgical metallurgy were quantitatively studied and predicted The results show that the results are in good agreement with the experimental results.

http://www.leapzipblog.com/blog/read/290939/the-importance-of-servo-motor-for-laser-cutting-machine/

http://laserman.doodlekit.com/blog/entry/4119940/analysis-of-laser-cutting-technology-of-seven-metal-materials

http://laserpointers.jigsy.com/entries/general/analysis-of-laser-cutting-technology-of-seven-metal-materials  
タグ :laser pointer


Posted by laserman at 16:33Comments(0)Technology