Transparent spinel ceramics and method for the production thereof

US9309156B2 · kind B2 · utility

Assignee

• Fraunhofer-Gesellschaft zur förderung der angewandten Forschung e.V. · DE

Inventors

• Thomas Hutzler · Dresden, DE
• Andreas Krell

Key dates

• Filing date: May 27, 2014
• Grant date: Apr 12, 2016
• Expiry date: May 30, 2034

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C04B2235/9653
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Transparent spinel ceramics, as they can be used, for example, as protective ceramics, and to a method for the production thereof.Transparent spinel ceramics which preferably contain no visible defects and which have an in-line transmission of more than 82% in wavelength ranges of infrared light, measured between 1000 nm and 2500 nm, at sample thicknesses≧3 mm.Spinel ceramics transparent in wavelength ranges of infrared light which are composed of sintered magnesium aluminum spinel having an average structural grain size of ≦10 μm and having maximally 0.5 mass % overall of homogeneously distributed additives of calcium and/or strontium and/or barium which are present in a concentration, expressed respectively as an oxide, of 0.005 to <0.2 mass % CaO and/or 0.005 to <0.5 mass % SrO and/or 0.005 to <0.5 mass % BaO.