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Title: The mechanical properties of T-111 at low to intermediate temperatures

Abstract

In the design of the 60-W Isotopic Heat Source (IHS), a tantalum alloy (T-111) strength member serves as the primary containment shell for the IHS during operation (He-gas internal environment and inert gas or vacuum external environment). An outer Hastelloy S clad is used to protect the T-111 from oxidation, and both the Hastelloy S clad and the T-111 strength member are sealed by automatic gas tungsten arc (GTA) welding. The expected life of the IHS is 5 years at about 650 C preceded by up to 5 years of storage at approximately 300 C. For this application, one important concern is failure of the T-111 strength member due to capsule pressurization arising from helium generation as a fuel decay product. To provide specific data on the mechanical behavior of base and solid metal T-111 under conditions appropriate to the IHS use conditions, a testing program was formulated and carried out. Three types of mechanical tests were conducted. Tensile properties were measured over the temperature range of 25 to 1100 C on T-111 base metal and samples with either longitudinal or transverse autogenous welds. Creep tests on base metal and samples with transverse welds were run to failure over themore » temperature range of 1100 to 850 C. Creep tests were also run on several transverse weld samples over the temperature range of 500 to 900 C at stresses where failure did not occur, and the creep rates were measured. Two prototypical capsules of the T-111 strength member were fabricated by EG and G Mound Applied Technologies (Mound Laboratories). To verify the mechanical properties design data developed above, these were tested to failure (leak) in a vacuum chamber with the inside of the capsule pressurized by either argon or helium.« less

Authors:
;
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Energy Research, Washington, DC (United States)
OSTI Identifier:
665943
Report Number(s):
ORNL/TM-13265
ON: DE98003603; TRN: 99:000153
DOE Contract Number:  
AC05-96OR22464
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Jan 1997
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 07 ISOTOPE AND RADIATION SOURCE TECHNOLOGY; RADIOISOTOPE HEAT SOURCES; TANTALUM BASE ALLOYS; TUNGSTEN ALLOYS; HAFNIUM ALLOYS; HASTELLOY S; CREEP; YIELD STRENGTH; ULTIMATE STRENGTH; ELONGATION; EXPERIMENTAL DATA; NESDPS Office of Nuclear Energy Space and Defense Power Systems

Citation Formats

McCoy, H E, and DiStefano, J R. The mechanical properties of T-111 at low to intermediate temperatures. United States: N. p., 1997. Web. doi:10.2172/665943.
McCoy, H E, & DiStefano, J R. The mechanical properties of T-111 at low to intermediate temperatures. United States. https://doi.org/10.2172/665943
McCoy, H E, and DiStefano, J R. 1997. "The mechanical properties of T-111 at low to intermediate temperatures". United States. https://doi.org/10.2172/665943. https://www.osti.gov/servlets/purl/665943.
@article{osti_665943,
title = {The mechanical properties of T-111 at low to intermediate temperatures},
author = {McCoy, H E and DiStefano, J R},
abstractNote = {In the design of the 60-W Isotopic Heat Source (IHS), a tantalum alloy (T-111) strength member serves as the primary containment shell for the IHS during operation (He-gas internal environment and inert gas or vacuum external environment). An outer Hastelloy S clad is used to protect the T-111 from oxidation, and both the Hastelloy S clad and the T-111 strength member are sealed by automatic gas tungsten arc (GTA) welding. The expected life of the IHS is 5 years at about 650 C preceded by up to 5 years of storage at approximately 300 C. For this application, one important concern is failure of the T-111 strength member due to capsule pressurization arising from helium generation as a fuel decay product. To provide specific data on the mechanical behavior of base and solid metal T-111 under conditions appropriate to the IHS use conditions, a testing program was formulated and carried out. Three types of mechanical tests were conducted. Tensile properties were measured over the temperature range of 25 to 1100 C on T-111 base metal and samples with either longitudinal or transverse autogenous welds. Creep tests on base metal and samples with transverse welds were run to failure over the temperature range of 1100 to 850 C. Creep tests were also run on several transverse weld samples over the temperature range of 500 to 900 C at stresses where failure did not occur, and the creep rates were measured. Two prototypical capsules of the T-111 strength member were fabricated by EG and G Mound Applied Technologies (Mound Laboratories). To verify the mechanical properties design data developed above, these were tested to failure (leak) in a vacuum chamber with the inside of the capsule pressurized by either argon or helium.},
doi = {10.2172/665943},
url = {https://www.osti.gov/biblio/665943}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 1997},
month = {Wed Jan 01 00:00:00 EST 1997}
}