Development of High Temperature Materials for Aero Engine Hot End Components: An Overview

Abstract

The present paper overviews the development of materials and superalloys for aero engine hot end components to meet the increasing trend of turbine inlet temperature. Requirement of higher and higher thrust is steadily increasing the turbine inlet temperature and the development of nickel-chromium superalloys in early 1940s could not fulfil the material capability for long. Various nickel-base superalloys developed in 1950s and 1960s could increase the life of hot end components by retaining strength and resisting oxidation at extreme temperatures. In the 1960s and 1970s, with almost stagnation in high temperature alloy development, metallurgists changed focus from alloy chemistry to alloy processing which evolved the directional solidification and single crystal casting technologies. At present, almost all fighter class engines and high bypass commercial engines are using nickel and cobalt base superalloys for hot end components and single crystal superalloys particularly for turbine blades. This paper covers the developmental phases of superalloys and casting technologies for engine hot end components. This paper will be an invaluable asset for the researchers as well as for designers of future gas turbine engines.