A THERMO-CHEMICAL APPROACH TO LASER CUTTING OF THICK METALLIC SOLIDS

MACHINING IS THE LARGEST SINGLE APPLICATION (OVER 50%) OF LASERS TO MATERIALS PROCESSING. LASER CUTTING OF METALLIC MATERIALS IS FINDING INCREASING USE IN INDUSTRIAL APPLICATIONS BUT IS GENERALLY LIMITED TO THIN SECTIONS (5MM). THICKER-SECTION METAL CUTTING WITH LASERS SUFFERS FROM SEVERAL DRAWBACKS THAT INCLUDE LACK OF HEAT PENETRATION, LARGE KERF WIDTH, POOR CUT QUALITY, AND PROBLEMS ASSOCIATED WITH MATERIAL REMOVAL AND HEAT TRANSFER. A THERMOCHEMICAL APPROACH INVOLVING THE APPLICATION OF TWO ADJACENT, HIGH-POWER LASER BEAMS IN GAUSSIAN ENERGY CONFIGURATION AND VARIOUS ORGANIC ASSIST GASES (C2H2, C3H8, AND C7H18) ALONG WITH OXYGEN IS PROPOSED TO EXTEND THE PERFORMANCE LIMITATIONS OF LASER CUTTING WITHOUT DETERIORATING THE CUT QUALITY. HEAT TRANSFER, FLUID FLOW, AND CHEMICAL REACTIONS PHENOMENA WILL BE UTILIZED TO DEVELOP THEORETICAL MODELS THAT WILL CLOSELY PREDICT THE EXPERIMENTAL RESULTS. THE MATHEMATICAL APPROACHCOMBINED WITH THE PROPOSED EXPERIMENTS WILL PROVIDE VALUABLEINSIGHT INTO THE NATURE OF PHYSICAL PHENOMENA, FACILITATING EFFICIENT LASER CUTTING OF MATERIALS MUCH THICKER AND FASTERTHAN THOSE THAT ARE POSSIBLE CURRENTLY. THE PROPOSED RESEARCH WILL BE PARTICULARLY ATTRACTIVE TO HIGH-TECHNOLOGY MANUFACTURING INDUSTRIES THAT USE LASER MACHINING.