Silicon Nitride for Gas Turbines

Published

August 1, 2001

Author(s)

Sheldon M. Wiederhorn, M Ferber

Abstract

Silicon nitride is a material with a high-temperature potential and, hence, an excellent candidate for gas turbines. The incentive to use silicon nitride is substantial, as higher operating temperatures can be translated directly into higher engine efficiency and a saving in operating costs. On this basis, several large programs were initiated on silicon nitride with the objective of producing a material capable of operating in a gas turbine, commencing in the early 70's and continuing through to the current time. Principal problems at the start of the program were poor creep resistance, low toughness and an unacceptable variation in strength. Although corrosion was not deemed important, corrosion in the turbine environment turned out to be one of the crucial impediments blocking the use of silicon nitride in turbines. Silicon nitride has been used in auxiliary power units on aircraft for many thousands of hours, and is available as a commercial material in this application. Its behavior in larger turbines is, however, marginal, and considerable improvement in performance is needed primarily as a consequence of foreign object impact damage and chemical attack by oxygen and water in gas tgurbine combusion gases. Here, we discuss the problems that have to be overcome for this mateiral to perform adequately in large gas turbines.

Citation

Current Opinion in Solid State & Materials Science

Volume

5

Issue

No. 4

Pub Type

Journals

Keywords

corrosion resistance, creep, high temperature, silicon nitride, strength, toughness

Citation

Wiederhorn, S. and Ferber, M. (2001), Silicon Nitride for Gas Turbines, Current Opinion in Solid State & Materials Science (Accessed July 22, 2024)