Aluminium Mirror Finish No Longer a Challenge

Kemet International launched their new Kemox SF slurry only 3 months ago and it has already been found to be the perfect solution for aluminium mirror polishing, prior to super finishing, by Professor David Walker, Professor of Ultra Precision Surfaces at Huddersfield University.

Their application involved polishing a 480mmø aluminium mirror for the LOCUS project. This being a proposed space mission to observe the Earth’s atmosphere at grazing incidence, giving long path-lengths, to measure pollutant chemical species. It is based on an off-axis Cassegrain telescope design, for cryogenic operation in the TeraHz (microwave) and near-infrared regions.

Locus M1 Polishing

The mirror was first CNC milled to generate an off axis parabolic surface, and then pre lapped to generate a uniform grey surface. A variety of polishing slurries were tested, but these couldn’t produce a uniform polished surface, and some crystallised too quickly, clogging up the dispenser system.

Kemet recognised these issues and supplied their Kemox SF slurry as a solution. This not only produced a uniform polished surface, but also reduced the polishing time and alleviated the slurry clogging issue. Finally the mirror was super finished using Kemet’s COL-K NC non-crystallising colloidal slurry producing a texture of 6nm.

From first contact with Kemet to producing a finished mirror took only 2 weeks. If you think you could benefit from Kemet’s 80 years in precision surface finishing, give them a call.

Locus M1 Polished