Mechanisms and Applications of Laser Chemical Machining

Metals can be machined with high quality by laser chemical processing. In this process, an etching liquid is injected coaxially to a laser beam directly into the irradiated area, leading to a material removal via chemical dissolution of the metal. It is shown that the reaction is temperature driven independent of the laser wavelength. A limiting factor is the diffusion of the anions identified by comparing experimentally determined and calculated diffusion coefficients for the reaction products. As applications, the fabrication of electron beam apertures and the finishing of micro forming tools are shown.