Observational astronomy has striven for better telescopes with higher resolutions from its start. This needs ever-larger mirrors with stable high precision surfaces. The extremely low expansion glass ceramic ZERODUR® enables such mirrors with more than 50 years of significant improvements in size and quality since its development. We provide a survey of the progress achieved in the last 15 years. The narrowest coefficient of thermal expansion (CTE) tolerance is now ±7 ppb / K. It is possible to adapt the material for lowest expansion to temperature-time courses given for special environments. At cryo temperatures, expansion is low and adaptable. Improved measurement capabilities allow for absolute CTE uncertainty of 3 ppb / K and reproducibility of 1 ppb / K (2σ). The influence of ionizing radiation on the surface figure integrity is subject to new investigations. Improved measurement capabilities increase the reliability of structure designs. Some outstanding examples are given for applications of ZERODUR in astronomy and in the very important high technology industry. The progress of thermal expansion homogeneity, the mechanical strength of ZERODUR, production capabilities in melting, precision machining, light-weighting, and dimensional metrology is presented in the second part of the paper.

中文翻译：

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玻璃陶瓷 ZERODUR ^®：更接近于零热膨胀：评论，第 1 部分

观测天文学从一开始就一直在努力寻找分辨率更高的更好的望远镜。这需要具有稳定高精度表面的更大的反射镜。极低膨胀玻璃陶瓷 ZERODUR® 使此类反射镜自开发以来在尺寸和质量方面取得了 50 多年的显着改进。我们对过去 15 年中取得的进展进行了调查。最窄的热膨胀系数 (CTE) 容差现在为 ±7 ppb / K。可以使最低膨胀的材料适应为特殊环境提供的温度-时间过程。在低温下，膨胀低且适应性强。改进的测量能力允许 3 ppb / K 的绝对 CTE 不确定度和 1 ppb / K (2σ) 的再现性。电离辐射对表面图形完整性的影响正在接受新的研究。改进的测量能力提高了结构设计的可靠性。ZERODUR 在天文学和非常重要的高科技行业中的应用给出了一些杰出的例子。论文的第二部分介绍了热膨胀均匀性、ZERODUR 的机械强度、熔融生产能力、精密加工、轻量化和尺寸计量方面的进展。