As the mainstream, traditional laser cutting uses CO2 laser, which can stably cut carbon steel within 20mm, stainless steel within 10mm, and aluminum alloy below 8mm. Fiber lasers have obvious advantages when cutting thin plates within 4 mm. Due to the wavelength of solid lasers, they are of poor quality when cutting thick plates. Of course, laser cutting machine is not omnipotent. The wavelength of CO2 laser is 10.6um. The wavelength of solid-state laser such as YAG or fiber laser is 1.06um. The former is easily absorbed by non-metals and can cut wood, acrylic, PP and plexiglass with high quality. Fiber laser is not easily absorbed by non-metals, so it is impossible to cut non-metallic materials, but the two lasers can’t help when they encounter high-reflection materials such as copper, silver, and pure aluminum.
It is precisely because the wavelengths of both CO2 and fiber lasers has big difference, the former cannot be transmitted by optical fibers, and the latter can be transmitted by optical fibers, which greatly increases the degree of flexibility of processing. In the early days before the introduction of fiber lasers, in order to realize three-dimensional processing, optical joint technology was used to guide the CO2 laser to the surface of the three-dimensional curved surface through a highly sophisticated combined dynamic mirror system to realize the three-dimensional processing of CO2 laser. The limitation of processing technology is mainly in the hands of a handful of developed countries in Europe and America. It is expensive and has high maintenance requirements. It has gradually lost its market while the market share of fiber laser is gradually expanding. The fiber laser can be transmitted through the optical fiber, and the degree of flexibility is unprecedentedly improved. Especially for automotive industry, since the thin plate surface processing is basically about 1 mm, the fiber laser is matched with the same flexible robot system, and the cost is low and the number of fault points is small. The maintenance is convenient, the speed is very fast, and the market is gradually occupied by fiber laser cutting.
The photoelectric conversion rate of fiber laser is up to 25%, and the photoelectric conversion rate of CO2 laser is only about 10%. The advantages of fiber laser in the cost of electricity consumption and supporting cooling system are quite obvious. However, fiber laser as an emerging laser technology is far less popular than CO2 laser. Its stability and reliability, and the convenience of after-sales service have yet to be observed in the market for a long time.
According to international safety standards, the laser hazard level is divided into 4 levels. The CO2 laser belongs to the lowest level of damage. The short-wavelength of the fiber laser is harmful to the human body due to the short wavelength. It is the most harmful level. For safety reasons, the fiber laser Processing requires a fully enclosed environment.
The direction of laser applications should be that high-power CO2 lasers are used on more stable, larger format, faster machines. Fiber lasers are more advantageous for surface machining up to 2mm.