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Candidate Materials Evaluated for a High-Temperature Stirling Convertor Heater HeadThe Department of Energy and NASA have identified Stirling Radioisotope Generators (SRGs) as a candidate power system for use on long-duration, deep-space science missions and Mars rovers. One of the developments planned for an upgraded version of the current SRG design is to achieve higher efficiency by increasing the overall operating temperature of the system. Currently, the SRG operates with a heater head temperature of 650 C and is fabricated from the nickel-base superalloy 718. The current operating temperature is at the limit of alloy 718 s capability, and any planned increase in temperature will be contingent on identifying a more capable material from which to fabricate the heater head. To this end, personnel at the NASA Glenn Research Center are evaluating advanced materials for a high-temperature heater head to allow a higher convertor temperature ratio and, thus, increase the system efficiency. A generic list of properties that were used to screen the candidate materials follows: (1) creep, (2) fabricability, (3) helium gas containment, (4) long-term stability and compatibility, (5) ability to form a hermetical closeout seal, and (6) ductility and toughness.
Document ID
Acquisition Source
Glenn Research Center
Document Type
Bowman, Randy R.
(NASA Glenn Research Center Cleveland, OH, United States)
Ritzert, Frank J.
(NASA Glenn Research Center Cleveland, OH, United States)
Date Acquired
September 7, 2013
Publication Date
June 1, 2005
Publication Information
Publication: Research and Technology 2004
Subject Category
Metals And Metallic Materials
Distribution Limits
Work of the US Gov. Public Use Permitted.
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