Manufacturing of lightweighted ZERODUR components at SCHOTT

Abstract

There is a broad range of applications for lightweighted components made from ZERODUR^(R) glass ceramic. The main markets are secondary and tertiary mirrors for astronomical telescopes, mirrors and structural components for satellites, and mechanical structures for industrial applications, mainly in microlithography. Prominent examples from astronomy are VLT-M3, GEMINI-M2, SOFIA-M1, MAGELLAN-M2, MMT-M2, and METEOSAT-SEVIRI. At SCHOTT components with blind or undercut semiclosed holes are manufactured, typically with circular, hexagonal, rectangular or triangular shapes. The classical grinding process results in weight reduction factors of about 70 %. By additional acid etching technologies even higher lightweighting factors and rib thicknesses below 1 mm have been achieved.