In industrial production, lasers are an indispensable tool for cutting automotive sheet metal, hardening turbine blades, welding spacecraft, and more. However, to date, industrial lasers have only been able to effectively perform a specific task—hardening, cutting, or welding metals—and lasers are often large and cumbersome. According to the website of the Fraunhofer Association of Germany on May 3, researchers from the Institute of Materials and Radiology (IWS) will present a new model at the 2007 International Application Laser and Optoelectronics Technology Trade Fair in Munich. Multi-purpose laser - a fiber laser system that not only hardens, cuts, but also welds metal if needed.
For a long time in the past, the application of fiber lasers was limited to electronic communication. In glass fibers that transmit telephone and network signals, the fiber laser's signal is just strong enough to deliver tiny pulses of light. In the past few years, fiber lasers have been developed to output light of several kilowatts of power, while the thickness is only 50 microns.
In the past, lasers were used for complex three-dimensional components only through a great deal of technical effort. The fiber has the advantage of being flexible and flexible like a cable, and the fiber laser can be used for devices with complex shapes. IWS researchers have equipped the newly developed laser-cutting and hardening system with a robotic arm that cleverly guides the fiber so that it can enter the corners where the most inaccessible parts of the complex are.
In addition, the fiber laser produces light at a wavelength of about 1 micron, which is very easily absorbed by steel and aluminum, and energy can easily penetrate the material. Therefore, at the same energy output and 10 micron wavelength, the fiber laser cutting speed is twice that of the carbon dioxide laser. And it can be used in many materials and can be easily and flexibly integrated into the production line.
“Our system is more suitable for small and medium-sized businesses because traditional single-task laser systems are not cost effective for them,†said Dr. Steffen Bon? of IWS. In the pilot program, the functionality of the system has been extended to soldering. Another advantage that makes it popular is the size - not counting the robotic arm, the fiber laser is about the size of a refrigerator, just half the CO2 laser.
According to reports, the versatility of the system is mainly due to the quality of the laser beam itself. The fibers produce very uniform light and a small focus. Therefore, the laser can concentrate energy more efficiently and operate more quickly and accurately. In addition, due to the improved focus capability, high-speed remote control is now possible from a farther work location.
Carbon dioxide lasers currently account for more than 90% of the market, but they are mainly used to cut metal plates, not for more complex geometries. Moreover, the carbon dioxide laser energy conversion rate is only 6% to 10%, and the fiber laser energy can reach 20%. According to the introduction, other advantages of fiber laser include compact structure and high service life.
Of course, in addition to carbon dioxide and fiber lasers, diode lasers have their own market. Like the fiber laser, it produces short-wavelength, easily absorbed light that easily penetrates the metal. Hardening requires a larger focus in order to process a larger surface in a short time; and for more accurate cutting, the smaller the focus, the better. This is a problem for diode lasers. Relatively speaking, diode lasers are cheaper, but they are not very useful for companies that need to cut and solder. In the future, fiber lasers can achieve these three functions. “The first fiber laser system has been used in the automotive industry,†said Dr. Thomas Himmer, Head of IWS Laser Cutting Applications.