ANALYTICAL COMPARISON BETWEEN LASER BEAM AND ELECTRON BEAM WELDING

Laser and electron beams are presently widely applied to many fields of material processing. Laser and electron beams produce the highest heat sources intensities used in welding process.This work investigates analytical comparison which discusses the differences and similarities between laser and electron beam welding.These comparisons have been made in three aspects. The first explains the main
physical characteristics of laser and electron beams as heat sources used for welding process, and shows the most important points of differences between the laser and electron beam in the generation and manipulation of the beams. The second aspect is the technological comparison that presents the performance of the  two beams in the fields of welding, and shows the power capability and efficiency, technical performances of beams, mathematical models applied and application fields. The third aspect is the economical comparison which shows the process economics such as; cost of machines,tooling, aintenance, infrastructure and preparation of workpieces.The results obtained from these comparisons have been presented in two methods.The first method includes explanations supported by graphical illustrations, while the second one includes comparison tables.The results show that the electron beam have power efficiency and depth of penetration higher than that of laser, but electron beam needs vacuum environment and protection against x-ray production in most cases. Laser beam is excellent in welding magnetic and non metallic materials (plastics) while electron beam welding is impossible to be used for these  materials.These beams have fundamentally different physical natures so that laser beam has special characteristics which is important for welding like the possibility of beam splitting, beam mobility, controllability and low beam distortion.The results also show that nearly similar capital cost is incurred for both laser and electron beam welding up to 5kW, while laser capital cost increases rapidly above the
5kW level.