Compatibility of potential reinforcing ceramics with Ni and Fe aluminides

Abstract

There is a great deal of interest in the possible utilization of intermetallic compounds in advanced high temperature gas turbine engines. These compounds exhibit a variety of promising properties, including reasonable strength, high melting points, relatively low densities, and good corrosion resistance. However, in general, they also show limited ductilities and toughness, and less than optimum creep strengths at elevated temperatures. In addition, in applications involving advanced gas turbine engines, it is often necessary for candidate materials to have large elastic moduli. The present study is part of a program whose objective is to identify a high temperature fiber reinforced composite. The approach adopted was to fabricate laboratory samples of the combinations of materials considered by Misra, in order to determine the extent to which the thermodynamic calculations can predict phase stability. As many of the ceramic phases considered are not currently available in fiber form, they were added as particulates to the alloy matrices. The ways in which the materials were produced and evaluated are described