Grain growth in Ir--0. 3% W alloys. [1583 to 1808/sup 0/K, activation energy] [electronic resource].
- Oak Ridge, Tenn. : Oak Ridge National Laboratory, 1977.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- Pages: 27 : digital, PDF file
- Additional Creators:
- Oak Ridge National Laboratory and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- The fuel cladding material for isotope heat sources operating above 1300/sup 0/C is currently an Ir--0.3 percent W alloy. The ductility of this material under high-temperature impact accident conditions is reduced by large grain sizes. Grain size as a function of time and temperature is required to determine the effects of high-temperature exposure during fabrication, assembly, ground testing, and operation of the heat source. The average grain diameter and the number of grains across the 0.64 mm (0.025 in.) cladding-wall thickness of several batches of Ir--0.3 percent W sheet is reported as a function of time at 1583 K (1310/sup 0/C), 1688 K (1415/sup 0/C), and 1808 K (1535/sup 0/C) up to 2000 hr. Growth rates were measured both perpendicular and parallel to the sheet surface in longitudinal cross sections of sheet samples. In alloys with Th, Al, Fe, Ni, and Rh dopant additions, the grain structure was elongated and grain growth was retarded. Grain size was measured by the line intercept method and the data were described by the grain growth equation, d/sup 2/--d/sub 0//sup 2/ = kt. An activation energy for grain growth was determined for each batch, in both the perpendicular and parallel directions. Abnormal grain growth was not observed within the time and temperature ranges of this experiment.
- Report Numbers:
- E 1.99:ornl-5233
- Other Subject(s):
- Iridium Base Alloys
- Grain Growth
- Tungsten Alloys
- Activation Energy
- Grain Size
- Heat Sources
- High Temperature
- Temperature Dependence
- Time Dependence
- Very High Temperature
- Crystal Structure
- Iridium Alloys
- Mechanical Properties
- Platinum Metal Alloys
- Tensile Properties
- Nesdps Office Of Nuclear Energy Space And Defense Power Systems
- Published through SciTech Connect.
Schaffhauser, A.C.; Harasyn, D.E.
- Funding Information:
View MARC record | catkey: 14462459