ZERODUR Glass Ceramics for High Stress Applications

摘要

Recently SCHOTT has shown in a series of investigations the suitability of the zero expansion glass ceramic material ZERODUR for applications like mirrors and support structures of complicated design used at high mechanical loads. Examples are vibrations during rocket launches, bonded elements to support single mirrors or mirrors of a large array, or controlled deformations for optical image correction, i.e. adaptive mirrors. Additional measurements have been performed on the behavior of ZERODUR with respect to the etching process, which is capable of increasing strength significantly. It has been determined, which minimum layer thickness has to be removed in order to achieve the strength increase reliably.New data for the strength of the material variant ZERODUR K20 prepared with a diamond grain tool D151 are available and compared with the data of ZERODUR specimens prepared in the same way. Data for the stress corrosion coefficient n of ZERODUR for dry and normal humid environment have been measured already in the 1980s. It has been remeasured with the alternative double cleavage drilled compression (DCDC) method.