High speed material processing of thick stainless steel with a chemical oxygen-iodine laser

Abstract

High speed cutting rates were recently measured for thick stainless steel using a 10 kilowatt chemical oxygen-iodine laser (COIL) at the Air Force’s Phillips Laboratory. The rates measured were comparable to those predicted by a model developed by researchers at Japan’s Applied Laser Engineering Center based on their measurements with a 1 kilowatt COIL. That model groups the properties of the laser beam and its interaction with material into two empirically-determined parameters and has been shown to be useful for comparing material processing performance for different lasers with different materials. Our results agree within a factor of two with the predicted rates for powers an order of magnitude higher than previously reported with a spot size of 1.3 millimeters with various material thicknesses. With the ability to transport the COIL beam through fiber optics at high power densities as previously shown in Japan, this scalability in material processing capability demonstrates the potential for the development of new industrial applications using fiber optics for high power beam delivery. Several concepts are presented to illustrate the use of COIL in industrial settings such as shipbuilding, heavy machinery manufacture, and nuclear power facility decontamination and dismantlement. Remote delivery of the beam has the advantage of removing the laser from the processing floor, thus addressing safety concerns associated with chemical laser operation while increasing the flexibility for cutting table layout to optimize production efficiency. This also allows for remote operations using robotic manipulators for material processing in hazardous environments or confined spaces. Proposed future studies include fiber optic transmission measurements, standoff cutting demonstrations, and thick metal welding performance measurements, as well as refining material processing models to increase their predictive capabilities.High speed cutting rates were recently measured for thick stainless steel using a 10 kilowatt chemical oxygen-iodine laser (COIL) at the Air Force’s Phillips Laboratory. The rates measured were comparable to those predicted by a model developed by researchers at Japan’s Applied Laser Engineering Center based on their measurements with a 1 kilowatt COIL. That model groups the properties of the laser beam and its interaction with material into two empirically-determined parameters and has been shown to be useful for comparing material processing performance for different lasers with different materials. Our results agree within a factor of two with the predicted rates for powers an order of magnitude higher than previously reported with a spot size of 1.3 millimeters with various material thicknesses. With the ability to transport the COIL beam through fiber optics at high power densities as previously shown in Japan, this scalability in material processing capability demonstrates the potential for the deve...