Abstract

In fast chemical degradation/vaporization processes, such as in CO₂ laser hole-drilling and cutting of highly absorbing and thermally-insulating sheet targets, loss of energy from the target region by thermal conduction (and the dimensions of any surrounding HAZ) may safely be neglected. An elementary energy balance theory then predicts both drilling and cutting speeds. If the laser beam's effective diameter, d, at the target is held constant, the conventional relation for cutting speed, V, beam power, P, and sheet thickness, Z, is obtained: V = k · P · Z^-1 · d^-1, where the constant, k, is a function of the sheet material's specific heat and vaporization parameters. This relation expresses the usual rule: V goes as Z^-1 for a fixed laser cutting installation.

© 1993 Optical Society of America