Product Code: JLA_2_1_23

Authors:
T. H. Kim
Charles E. Albright
Schichan Chiang
Department of Welding Engineering, The Ohio State University, 190 W. 19th Ave., Columbus, Ohio 43210

The process efficiency of laser beam welding was measured as a function of travel speed. Temperature measurements were carried out during the bead‐on‐plate laser welding of mild steel with a focused 2KW CO₂ laser beam at various welding travel speeds. The laser welding process efficiency (power delivered to work/power in the beam) was calculated from the ratio of the heat content of the welded the specimen to the available laser beam energy (power × time). In the deep penetration welding region at intermediate travel speeds, the laser beam welding process efficiency (equal to the beam absorptance) was about 65%; but it was only about 28% in the shallow penetration region at high travel speeds. In deep penetration welding, multiple reflections within the penetration cavity enhance absorptance. A calculation based on four reflections within the cavity can account for the observed process efficiency.