Berlin 2018 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

MM: Fachverband Metall- und Materialphysik

MM 47: Poster Session II

MM 47.42: Poster

Wednesday, March 14, 2018, 18:30–19:45, Poster C

Ultra-precision surface figuring of aluminium mirror devices — •Jens Bauer, Melanie Ulitschka, Frank Frost, and Thomas Arnold — Leibniz-Institut für Oberflächenmodifizierung, Permoserstraße 15, D-04318 Leipzig, Germany

Technical aluminium alloy materials as AL6061 or AL905 are widely used in manufacturing of high performance mirror devices in the IR spectral range. However, the requirements in the optical surface quality increase tremendously for short-wavelength applications in the visible and UV range. Reactively-driven ion beam tools allow the direct surface figure error-correction of aluminium mirror optics for the first time up to 1 micron in height while preserving the surface roughness. A deterministic machining approach with a small-sized tool is applied to perform ultra-precise figuring of diversely shaped surfaces as spheres, aspheres or even freeforms. As an example the figure error correction of a deep concave parabolic mirror with an aspect ratio of central depth to open aperture of about 0.6 is presented. The contribution comprises technological aspects as the generation of a focused millimeter sized ion beam, the evaluation of different machining geometries within the particular ion beam erosion model scheme, and several trial process applications of reactive ion beam machining at aluminum sample devices.