Overview of the three major parts of laser technology

The first laser beam in the world was produced by using a flash bulb to excite ruby u200bu200bcrystal grains in 1960. Due to the limitation of the heat capacity of the crystal, it can only produce a very short pulse beam and the frequency is very low. Although the instantaneous pulse peak energy can be as high as 10^6 watts, it is still a low energy output.

The 'tool' used in laser processing is the focused light spot. No additional equipment and materials are needed. 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, and no human intervention is required during production.

Currently, laser processing technology includes three areas, laser marking, laser cutting, and laser welding. The development of laser technology has promoted the development of the entire industry, so what is the situation of the three major parts of laser technology?

Laser marking technology is one of the largest application areas of laser processing. Laser marking is a marking method that uses high-energy-density lasers to locally irradiate the workpiece to vaporize or change the color of the surface material, thereby leaving a permanent mark. Laser marking can produce various characters, symbols and patterns, etc., and the size of the characters can range from millimeters to micrometers, which has special significance for the anti-counterfeiting of products. The focused ultra-fine laser beam is like a tool, which can remove the surface material of the object point by point. Its advanced nature is that the marking process is non-contact processing, which does not produce mechanical extrusion or mechanical stress, so it will not damage the processed article; The size of the laser focused is small, the heat-affected area is small, and the processing is fine. Therefore, some processes that cannot be achieved by conventional methods can be completed.

Laser cutting technology is widely used in the processing of metal and non-metal materials, which can greatly reduce processing time, reduce processing costs, and improve workpiece quality. Modern lasers have become the 'sword' of 'cutting iron like mud' that people dream of pursuing.

Laser cutting is achieved by applying high power density energy generated by laser focusing. Under the control of the computer, the laser is discharged through pulses, thereby outputting a controlled repetitive high-frequency pulsed laser to form a beam with a certain frequency and a certain pulse width. The pulsed laser beam is guided and reflected by the optical path and focused by the focusing lens group. On the surface of the processed object, a small, high-energy-density light spot is formed. The focal spot is located near the surface to be processed, and the processed material is melted or vaporized at an instant high temperature. Each high-energy laser pulse instantly sputters a small hole on the surface of the object. Under computer control, the laser processing head and the processed material perform continuous relative movement according to the pre-drawn graphics, so that the object will be processed into The shape you want. When cutting, a stream of air coaxial with the beam is ejected from the cutting head to blow the melted or vaporized material from the bottom of the incision. The additional energy required; the airflow also cools the cut surface, reduces the heat-affected zone and ensures that the focusing lens is not polluted). Compared with traditional plate processing methods, laser cutting has high cutting quality (narrow cut width, small heat-affected zone, smooth cut), high cutting speed, high flexibility (can cut any shape at will), and a wide range of materials Adaptability and other advantages.

Laser welding is one of the important aspects of the application of laser material processing technology. The welding process is thermally conductive, that is, the surface of the workpiece is heated by laser radiation, and the surface heat is diffused into the interior through thermal conduction. By controlling the width and energy of the laser pulse Parameters such as, peak power and repetition frequency make the workpiece melt and form a specific molten pool. Because of its unique advantages, it has been successfully used in the welding of micro and small parts. The emergence of high-power CO2 and high-power YAG lasers opened up a new field of laser welding. It has obtained the deep welding based on the pinhole effect and has been widely used in machinery, automobile, steel and other industrial sectors.

Laser welding technology can weld hard-to-reach parts, and implement non-contact long-distance welding, which has great flexibility. The use of optical fiber transmission technology in YAG laser technology has made laser welding technology more widely promoted and applied. The laser beam is easy to realize the beam splitting according to time and space, and can perform multi-beam simultaneous processing and multi-station processing, which provides conditions for more precise welding.