Ytterbium Silicate Fibers: Fabrication, Microstructure and Strength

Abstract

High temperature ceramic and metal matrix composites, which are to be used under complicated loading conditions in a severe atmosphere, have to satisfy a large number of the requirements. Hence, development of such composites calls for a large variety of fibers, matrices and interface materials to make an appropriate choice in designing a particular composite. The fiber is definitely the most important component of a composite. The family of oxide fibers is the most important among possible reinforcements for metal and oxide matrices. In this work, a family of potential oxide reinforcements containing ytterbium monosilicate Yb2SiO5 and disilicate Yb2Si2O7, and ytterbia-ytterbium monosilicate eutectic, was obtained and studied. The interest in those silicates was aroused because (i) they are highly resistant to hot corrosion in the presence of water vapor and (ii) their CTE varies from 8 × 10−6 K−1 for monosilicate to 4 × 10−6 K−1 for disilicate.