Ytterbium Silicate Fibers: Fabrication, Microstructure and Strength

Sergei Mileiko,Maxim Nikonovich,Olga Shakhlevich,Sergei Galyshev,Andrew Kolchin

doi:10.3390/fib7120104

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.

Highlights

Replacing nickel superalloys in gas turbine applications with high-temperature, fibrous composites is an urgent problem; by solving it, mankind will obtain a clearer environment as a result of enhancing the temperatures in combustion chambers and decreasing fuel consumption. The development of such composites is a highly complicated problem that calls for the availability of a large variety of fibers with various mechanical, physical and chemical properties
Crystallizing oxide fibers from the melt by well-known, traditional methods yields fibers of perfect microstructures and excellent properties, but they are too expensive to be used in structural composites [5]
Room and high temperature strengths of various fibers based on ytterbium silicates

Summary

Introduction

Replacing nickel superalloys in gas turbine applications with high-temperature, fibrous composites is an urgent problem; by solving it, mankind will obtain a clearer environment as a result of enhancing the temperatures in combustion chambers and decreasing fuel consumption. The fabrication technology, microstructure and strength of a family of the potential oxide reinforcements containing ytterbium monosilicate Yb2 SiO5 and disilicate Yb2 Si2 O7 , and ytterbia-ytterbium monosilicate eutectic, are presented. The interest in those silicates was aroused because (i) they are highly resistant to hot corrosion in the presence of water vapor [8,9,10] and (ii) their. Should stimulate further searching for and studies of fibers not reported in the literature yet

Fabrication of the Fibers

Si2 O7

Microstructure of the Fibers

Strength of the Fibers

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Conclusions