Applications of composite gas turbine components. Semi-annual technical progress report, Phase 1

Phase I of this program evaluates several nickel base superalloy combinations which have been diffusion bonded using hot isostatic pressing (HIP). This technique enables large gas turbine buckets to be fabricated using materials with improved creep and low-cycle fatigue life for the airfoil and greater high-temperature tensile strength in the dovetail. The program will specifically investigate three directionally solidified airfoil alloys and two powdered metal dovetail alloys. This effort will include heat treat studies, physical metallurgy and high-temperature tensile testing for all five alloys in their HIP bonded condition. In parallel with these tasks will be studies of mechanics of materials and mechanical design considerations for adapting composite bucket technology into advanced gas turbine designs.