Development of Fiber Laser Weld Parameters for Stainless Steel and Refractory Metals

摘要

Laser welds were made in 21-6-9 stainless steel, vanadium and tantalum using LLNLs new 6kW fiber laser to target 1 mm penetration depths. The materials were machined into flat coupon samples with standard step-joint geometries, and were welded in a continuous wave mode. The laser was characterized using the Primes laser beam diagnostic system so that the beams can be reproduced in the future. The optical configuration consisted of a 200 micro m fiber, 200 mm collimator and 250 mm focusing lens, which delivered electron-beam level power densities in the 5 to 20 kW/mm2 range. The three different materials required different power densities to produce the desired penetration, and this report summarizes the results of this screening study that was directed at developing a first approximation to the proper welding parameters for future work.