Effect of inclination angle on the absorptance of a graphite-coated cold-rolled steel sheet irradiated by laser

Abstract

This work presents an experimental-numerical methodology aimed at deriving the relation betweenabsorptance and incident angle of a randomly polarized Yb fiber-laser beam applied to a graphitecoatedstainless steel cold-rolled sheet. The absorptance values were obtained by minimizing theerror between temperature evolution measurements at various locations of the irradiated sheet andthe corresponding finite element predictions. The absorptance was found to increase from 0.66 to0.71 in the region between 0 and 10, to return to the original value between 10 and 20, toremain relatively constant between 20 and 50, and then to drop sharply between 50 and 80 finishingat 0.44. Furthermore, the consequences of these results in the laser bending process are analyzed.