Mar 02, 2020
With the development of semiconductor chip technology and optical technology, the output power of semiconductor lasers has been continuously improved, the beam quality has been significantly improved, and more applications have been obtained in the industrial field. At present, the output power and beam quality of industrial high-power semiconductor lasers have surpassed lamp-pumped YAG lasers, and are close to semiconductor-pumped YAG lasers. Semiconductor lasers have gradually been applied to plastic welding, cladding and alloying, surface heat treatment, metal welding, etc., and have also made some application progress in marking, cutting, and other aspects.
1. Laser plastic welding
The beam of a semiconductor laser is a flat-topped beam, and the spatial distribution of cross-section light intensity is relatively uniform. Compared with the beam of the YAG laser, the beam of the semiconductor laser in plastic welding applications can obtain better weld consistency and welding quality and can perform wide-slot welding. The power requirements of semiconductor lasers for plastic welding applications are not high, generally 50 ~ 700W, the beam quality is less than 100mm / mrad, and the spot size is 0.5 ~ 5mm. Welding with this technique does not damage the surface of the workpiece, local heating reduces the thermal stress on the plastic parts, can avoid damaging the embedded electronic components, and better avoids plastic melting. By optimizing raw materials and pigments, laser plastic welding can obtain different synthetic colors. At present, semiconductor lasers have been widely used for welding components such as sealed containers, electronic component housings, automotive parts, and heterogeneous plastics.
2. Laser cladding and surface heat treatment
Surface heat treatment or local cladding of metal parts with high requirements on wear resistance and corrosion resistance is an important application of semiconductor lasers in processing. Internationally, semiconductor lasers used for laser cladding and surface heat-treatment have a power of 1 to 6 kW, a beam quality of 100 to 400 mm / mrad, and a spot size of 2 × 2 mm 2 to 3 × 3 mm 2 or 1 × 5 mm 2. Compared with other lasers, the advantages of cladding and surface heat treatment with semiconductor laser beams are high electro-optical efficiency, high material absorption, low maintenance costs, rectangular spot shape, and uniform light intensity distribution. At present, semiconductor laser cladding and surface heat treatment have been widely used in electric power, petrochemical, metallurgical, steel, machinery and other industrial fields, and have become one of the important means for the preparation of new materials, rapid and direct manufacturing of metal parts, and green remanufacturing of failed metal parts.
3. Laser metal welding
High-power semiconductor lasers have many applications in metal welding, ranging from precision spot welding in the automotive industry to heat conduction welding of production materials, and axial welding of pipes. The quality of their welds is good and no subsequent processing is required. The semiconductor laser used for sheet metal welding requires a power of 300-3000W, a beam quality of 40-150mm / mrad, a spot size of 0.4-1.5mm, and a thickness of the welding material of 0.1-2.5mm. Due to the low heat input, distortion of the parts is kept to a minimum. High-power semiconductor lasers can perform high-speed welding with smooth and beautiful welds. It has special advantages in terms of labor-saving during and after welding and is very suitable for the different needs of industrial welding. It will gradually replace traditional welding methods.
4. Laser Marking
Laser marking technology is one of the largest application areas of laser processing. Currently used lasers include YAG lasers, CO2 lasers, and semiconductor pump lasers. But with the improvement of semiconductor laser beam quality, semiconductor laser marking machines have begun to be used in the field of marking.
5. Laser cutting
The application of high-power semiconductor lasers in the cutting field started late. With the support of the "Modular Semiconductor Laser System" (MDS) program of the German Ministry of Education and Research, the Fraunhofer Institute in Germany developed a semiconductor laser cutting machine with a power of 800W in 2001. 0.4m / min.