Experimental and Numerical Investigation of Micromachining by Laser-induced Electrochemical Process

In order to further understand behavior of laser-induced electrochemical etching process, laser electrochemical etching metal heated rapidly by laser in the electrolyte was investigated, both experimentally and theoretically. For the first time, 808 nm semiconductor laser was adopted for the process with the stainless-steel sample in sodium nitrate solution. Thermal phenomena adjacent to the metal-liquid interfaces induced by laser heating with the power of 10 ⁴-10⁵ W/cm² were also numerically investigated. Laser-enhanced photothermal process increases etching velocity, however, it leads to transverse etching. To reduce the transverse etching, laser scanning was also adopted to pattern on the stainless steel. In this study, the experimental results indicate this method can meliorate the transverse etching, improve the etching quality and a minimum figure line-width of 62.5 mum was obtained. In the meantime, it is validated by numerical and experimental study that 808 nm laser-induced electrochemical etching process contains the characteristics of laser-enhanced photothermal effect