Directional Solidification of Land-Based Gas Turbine Buckets
Improvements in land-based gas turbine performance require materials capable of operating at increasingly higher temperatures. Innovative approaches to alloy and process improvement, such as directional solidification, can meet the more demanding conditions of new gas turbine designs. This paper outlines GE TBO’s multi-faceted research program for the development of directionally solidified GTD-111 first stage turbine buckets. Included are discussions of the theoretical background, casting program, mechanical tests and machining studies. The GTD-111 directional solidification program successfully met the technological challenges encountered in scaling up directional solidification experience from relatively small aircraft parts. Directionally solidified buckets are in production for several first stage product lines. Improvements in mold technology coupled with experience gained in the on-going research program indicate that more complex parts as well as single crystal parts are now feasible.