Progress on Ceramic Rotor Blade Development for Industrial Gas Turbines

Abstract

This paper reviews progress made in the first year of a three-year program sponsored by EPRI to design and test ceramic root attachments, leading to the full development of ceramic rotor blades and cantilevered vanes intended for industrial gas turbines. Initial work has focused on a rotor blade attachment design. The specific rotor configuration chosen for development consists of a cooled low-alloy steel disk, a cooled intermediate super-alloy attachment piece, an uncooled ceramic blade, and the provision for a compliant interface at the ceramic/metal root attachment. A new root attachment design, in which the root and groove are curved in their transverse and longitudinal directions, is presented. Room temperature spin tests of dovetail root forms have provided encouraging results and indicate that continued development is warranted.