Materials Processing
Lasers are the most versatile and flexible sources for materials processing. Fiber lasers offer the ultimate in solid state reliability and convenience. The advantages of high power fiber lasers over both conventional processing and processing with other laser types have made them the preferred choice for cutting, drilling, welding, brazing, soldering, marking, engraving, cladding, sintering and surface treatment.
Laser cutting is by far the largest application area in materials processing. Today, fiber lasers dominate this area since the required parameters for cutting are very well suited to them. Basically, laser cutting is achieved by heating the material above its melting point and removing it by a gas jet or just vaporization. The assisting gas can be a pressurized inert gas, air or O2. In case of O2, it helps cutting process by reacting exothermically with the material itself.
Laser drilling is prefered over conventional methods mainly because of its non-contact nature which eliminates tool wearing and reduces thermal loads. It is also possible to drill extremely small diameter (10 µm) holes. Basically, there are two drilling techniques. In percussion drilling, laser beam is focused at a point where a spot-size-diameter hole is created. In trepanning drilling, which is used for large diameter holes, the laser beam tracks the hole contour.
Marking & engraving are essential and widely used processes in manufacturing. Lasers are well suited for this application because of their reliable operation where no inks/dyes are needed. Laser marking is usually achieved by forming an oxide layer on the surface or by removing the coating layer if the surface is already coated. On the other hand, the main mechanism of engraving is vaporization. In recent years, nanosecond-pulsed Q-switched fiber lasers dominate this market because of their high beam qualities, high efficiencies and unrivaled costs-of-ownership.
Laser welding is applicable for both metals and polymers. Metal welding is based on creating a melting pool at the contact point of two metal pieces. High power CW fiber lasers are suitable for this application. However, QCW fiber lasers are preferable for spot welding aplications in which high peak power is only needed for a short amount of time (few milliseconds). Polymer welding requires 2 µm wavelength where the absorption is higher. Fiblas offers medium power Tm fiber lasers for this purpose.
Brazing process is similar to soldering from the point of laser processing. Two substrates are joint together by melting a filler material in-between which have a lower melting temperature. For example, steel and aluminum are one of the most common incompatible pairs to weld so a brazing process is needed to join them by using a zinc based filler. CW fiber lasers are well suited for brazing which are also considered as a high-precision alternative to soldering irons or hot air guns.
Laser based methods are prefered over abrasive/chemical processes since they are environmentally clean and cost effective. By using the correct laser parameters, it is possible to remove the surface coating or paint without damanging the underlying substrate. This process finds a large usage area in aerospace, automotive and ship building industries. It is also applicable to restoration of historical artifacts.
Additive manufacturing is currently one of the fastest developing applications. 3D shapes can be built layer-by-layer from many materials including metals. In SLM (selective laser melting) technique, the required regions of a thin metal powder layer are fused by a focused laser beam to form a thin section of the final product. Then the process continues by placing new powder layers on top of each other and fusing them together. Finally, the desired 3D shape is obtained with near full density and mechanical strength. Fiblas offers high power single-mode fiber lasers for this application.