Review of oxidation of Nb-1Zr
Abstract
A major objective of the SP-100 Program Nuclear Assembly Test is to demonstrate the performance of a full-scale nuclear subsystem of a 100-kWe space nuclear power supply. The test will be run in a large vacuum chamber to protect the Nb-1Zr components from oxidation during operation. Much information about the oxidation of niobium and Nb-1Zr alloy already exists, and previous work in this area is reviewed. Oxidation of Nb-1Zr can proceed by solution, internal oxidation, and/or film formation. At temperatures up to about 650 K (377 C), oxidation generally follows a parabolic rate law because of the formation of protective oxide(s). At higher temperatures, oxidation becomes linear, but results are extremely sensitive to pressure and other system variables. Results obtained by several investigators could not be predicted using empirical equations developed by one investigator relating the increase in oxygen concentration to pressure, temperature, time, and specimen thickness. Additional data are required to provide more reliable guidelines for system operation that will protect against catastrophic effects.
- Publication:
-
Unknown
- Pub Date:
- April 1989
- Bibcode:
- 1989ronz.rept.....D
- Keywords:
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- Niobium Alloys;
- Oxidation;
- Oxidation Resistance;
- Thin Films;
- Zirconium Alloys;
- Lithium;
- Pressure Effects;
- Space Power Reactors;
- Spacecraft Power Supplies;
- Temperature Effects;
- Thickness;
- Time;
- Nuclear and High-Energy Physics