Microindentation hardness evaluation of iridium alloy clad vent set cups

Conference · Thu Jan 14 23:00:00 EST 1993 · AIP Conference Proceedings (American Institute of Physics); (United States)

DOI:https://doi.org/10.1063/1.43196· OSTI ID:6807164

Ulrich, G B; DeRoos, L F; Stinnette, S E ^[1]

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1. Oak Ridge Y-12 Plant, P.O. Box 2009, Oak Ridge, Tennessee 37831-8096 (United States)

An iridium alloy, DOP-26, is used as cladding for [sup 238]PuO[sub 2] fuel in radioisotope heat sources for space power systems. Presently, DOP-26 iridium alloy clad vent sets (CVS) are being manufactured at the Oak Ridge Y-12 Plant for potential use in the National Aeronautics and Space Administration's Cassini mission to Saturn. Wrought/ground/stress relieved blanks are warm formed into CVS cups. These cups are then annealed to recrystallize the material for subsequent fabrication/assembly operations as well as for final use. One of the cup manufacturing certification requirements is to test for Vickers microindentation hardness. New microindentation hardness specification limits, 210 to 310 HV, have been established for a test load of 1000 grams-force (gf). The original specification limits, 250 to 350 HV, were for 200 gf testing. The primary reason for switching to a higher test load was to reduce variability in the test data. The DOP-26 alloy exhibits microindentation hardness load dependence, therefore, new limits were needed for 1000 gf testing. The new limits were established by testing material from 15 CVS cups using 200 gf and 1000 gf loads and then statistically analyzing the data. Additional work using a Knoop indenter and a 10 gf load indicated that the DOP-26 alloy grain boundaries have higher hardnesses than the grain interiors.

• OSTI ID: 6807164
• Report Number(s): CONF-930103--
• Journal Information: AIP Conference Proceedings (American Institute of Physics); (United States), Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Vol. 271:2; ISSN 0094-243X; ISSN APCPCS
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
070300* -- Isotopic Power Supplies
36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
ANNEALING
CLADDING
CONTAMINATION
CRYSTAL STRUCTURE
DATA
DEPOSITION
ELECTRONIC EQUIPMENT
EMBRITTLEMENT
ENCAPSULATION
EQUIPMENT
GRAIN BOUNDARIES
GRAIN SIZE
HARDNESS
HEAT SOURCES
HEAT TREATMENTS
INFORMATION
IRIDIUM ALLOYS
MATERIALS TESTING
MECHANICAL PROPERTIES
MICROHARDNESS
MICROSTRUCTURE
NESDPS Office of Nuclear Energy Space and Defense Power Systems
NUMERICAL DATA
PLATINUM METAL ALLOYS
POWER SUPPLIES
RADIOISOTOPE HEAT SOURCES
RECRYSTALLIZATION
SIZE
SPACECRAFT POWER SUPPLIES
STATISTICAL DATA
SURFACE COATING
TESTING
VICKERS HARDNESS