Читать книгу Encyclopedia of Glass Science, Technology, History, and Culture - Группа авторов - Страница 136

Known as S‐glass, fibers primarily composed of MgO, Al₂O₃, and SiO₂ were first developed in the late 1960s for high‐temperature and high‐strength applications and further expanded into military ballistic protection applications in the 1970s [6]. Because of high liquidus temperature (1470 ^oC), fibers must be drawn at temperatures significantly greater than 1500 ^oC to avoid fiber breakage caused by crystallization as the fibers are formed. This property attribute means that S‐glass fibers must be drawn in a much lower viscosity range than that of typical commercial fibers (Section 3.2). The challenges of this severe process limit the number of product forms and result in very high costs that have limited the commercial utility of S‐glass fibers to high‐performance markets such as aerospace and military applications where strength and weight combined can justify a premium over other materials. There are no large‐scale commercial production platforms in the S‐glass family. Derivatives of S‐glass have been investigated through introduction of small amounts of B₂O₃ and other oxides (Li₂O, CeO₂) to improve glass melting and fiber‐forming performance. To date no large commercial‐scale production has materialized.