Applications of composite gas-turbine components. Final report. Phase I

Technical Report · Wed Dec 01 04:00:00 EST 1982

OSTI ID:6777494

Peterson, L G; Hrencecin, D E

Heavy-duty, air-cooled gas turbines utilize relatively large superalloy buckets and nozzle guide vanes. These large components, particularly buckets, must demonstrate a variety of properties. The bucket airfoil requires excellent surface stability with high creep and low-cycle fatigue strength. The dovetail requires excellent tensile strength and low-cycle fatigue properties. Conventional buckets are fabricated as a single casting or forging in which compromises in these properties are inevitable, and the full capabilities of the superalloys used are rarely optimized with respect to each specific requirement. A unique approach toward improved performance in key properties is to integrate the best material for each part of a hot section bucket or nozzle into a bonded composite (or hybrid) component. A hybrid bucket is a gas turbine part composed of a variety of alloys bonded into one integral component. Each segment is tailored to perform a specific function with greater reliability and performance than possible with contemporary monolithic parts. An example is a directionally solidified airfoil vane bonded to a dovetail section of forged/PM superalloy. 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 on mechanics of materials and mechanical design considerations for adapting composite bucket technology into advanced gas turbine designs.

• Research Organization: General Electric Co., Schenectady, NY (USA). Gas Turbine Div.
• DOE Contract Number: AC01-80ET17005
• OSTI ID: 6777494
• Report Number(s): DOE/ET/17005-3; ON: DE83006574
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104* -- Fossil-Fueled Power Plants-- Components
36 MATERIALS SCIENCE
360300 -- Composite Materials-- (-1987)
360600 -- Other Materials
ALLOYS
COMBINED-CYCLE POWER PLANTS
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
DESIGN
FABRICATION
FATIGUE
GAS TURBINES
HEAT TREATMENTS
MACHINERY
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
POWER PLANTS
TESTING
THERMAL POWER PLANTS
TURBINE BLADES
TURBINES
TURBOMACHINERY