Three fields of application of laser technology in China
Laser marking technology, laser cutting technology and laser welding technology are three major fields of laser technology in our country.
Laser marking technique
Laser marking technology is one of the most important applications in laser processing. Laser marking is a marking method that uses high energy density laser to irradiate the workpiece locally, make the surface material vaporize or change the color of the chemical reaction, thus leaving a permanent mark. Laser marking can play a variety of characters, symbols and patterns and so on. The size of the character can be from millimeter to micrometer, which is of special significance to the anti-counterfeiting of the products. After focusing very fine laser beam as the tool, can make the material surface by removing, lies in its advanced marking process for non-contact processing, no mechanical extrusion or stress, processed items so will not be damaged; because the laser is very small in size, small heat affected zone, fine processing therefore, technology can complete some conventional methods can not be achieved.
The "tool" used in laser processing is the light spot after focusing. There is no need to add additional devices and materials. As long as the laser can work normally, it can be processed continuously for a long time. The laser processing speed is fast and the cost is low. Laser processing is automatically controlled by a computer without human intervention in production.
The laser can mark what information, and only the computer design related content, as long as the computer designed artwork marking system can be identified, then the marking machine can be designed with accurate information reduction in an appropriate carrier. So the function of the software is largely determined by the function of the system.
Laser cutting technology
Laser cutting technology is widely used in the processing of metal and non-metallic materials, which can greatly reduce the processing time, reduce the processing cost and improve the quality of the workpiece. Modern laser became people's pursuit of "standing" fantasy "sword". In our CO2 laser cutting machine as an example, the whole system is composed of control system, motion system, optical system, cooling system, exhaust and air protection system composed by numerical control mode of the most advanced multi axis machining and laser is not affected by the speed of energy cutting, and support DXP, PLT, CNC and other graphic formats and strengthen the interface graphics processing ability; the superior performance of the servo motor and drive guide structure to achieve good accuracy in motion under high speed.
Laser cutting is realized by using high power density energy produced by laser focusing. Under the control of the computer, through the pulse of the laser discharge, high pulse repetition frequency to output controlled laser, the formation of a certain frequency, the beam pulse, the pulse laser beam through the optical transmission and reflection and the focusing lens group focusing on processing objects on the surface, forming a high energy density fine and the spot, the focal spot is located in the vicinity of the surface to be processed, the instantaneous high temperature melting or vaporization of the material to be processed. Every high-energy laser pulse spatter a tiny hole on the surface of the object in a short time. Under the control of computer, the laser processing head and the processed material are continuously moved relative to each other according to the pre painted figure, so that the object will be processed into the desired shape. When cutting, a coaxial beam and the airflow from the cutting head will be ejected, melting or vaporization of material from the bottom of the incision blow out (Note: if the gas blowing and cutting material thermal reaction, the reaction will provide additional energy; cutting required airflow and cooling have been cut, cut the heat affected zone and ensure the focus lens contamination effect). Compared with traditional plate processing methods, laser cutting has the advantages of high cutting quality (narrow incision width, small heat affected zone, smooth incision), high cutting speed, high flexibility (optional cutting any shape), and extensive material adaptability.
Laser welding technology
Laser welding is one of the important applications of laser material processing technology, welding process of heat conduction, laser radiation heating surface, surface heat through the heat transfer oriented internal diffusion, by controlling the pulse width and energy, peak power and repetition frequency parameter, the melting pool specific form. Because of its unique advantages, it has been successfully applied to the welding of small and small parts. The emergence of high power CO2 and high power YAG lasers has opened up a new field of laser welding. Deep penetration is obtained based on the theory of small hole effect, which has been widely used in machinery, automobile, steel and other industrial sectors.
Compared with other welding techniques, the main advantages of laser welding are: laser welding speed, depth, and small deformation. It can be welded at room temperature or under special conditions, and the equipment is simple. For example, if the laser passes through the electromagnetic field, the beam will not be deflect. The laser can be welded in air and some gas environment, and can be welded through glass or transparent material to the beam. After laser focusing, the power density is high, the depth to width ratio can reach 5:1 and up to 10:1 when the high power device is welded. Welding refractory materials, such as titanium and quartz, can be welded to the heterosexual materials, and the effect is good. For example, the two materials of different properties of copper and tantalum are welded together, with a qualified rate of almost one hundred percent. Micro welding can also be carried out. By focusing laser beam can be obtained after a small spot, and precision positioning, micro and small element can be used for batch automatic production of welding, for example, integrated circuit lead, hairsprings, kinescope electron gun assembly due to the use of laser welding, not only the production efficiency, and high. Small heat affected zone, no pollution of solder joints,