Applications

SEM image collage of structures ablated in stainless steel, before and after laser polishing. Typical micro-cone structure (bottom, left) and smoothing with GHz burst mode (right).
Courtesy of Laserinstitut Hochschule Mittweida.

Stainless steel polishing is a finishing technique to achieve a specific or unique finish to a metal surface.

Stainless steel is a widely used alloy with rust-free and heat-resistant properties. Various applications, from consumer electronics to medical tools manufacturing, use stainless steel. Femtosecond lasers can engrave numerous types of stainless steel and change its surface properties.

Ultrashort pulsed laser radiation forms a typical micro-cone structure. The measured roughness of the structure is Sa approx. 6 µm, Sq approx. 8 µm and Sz over 30 µm. As a result, the bottom of the structure looks dark grey and does not have a metallic shine. It is possible to completely smooth the micro-cone structure by subsequent smoothing with GHz burst mode. This smoothing results in roughness with Sa and Sq below 0.2 µm and Sz below 2 µm.