Abstract
The activation energy for creep of nominally pure columbium (niobium) was determined in the temperature range 0.4 to 0.757TM by measuring strain rate changes induced by temperature shifts at constant stress. A peak in the activation energy vs temperature curve was found with a maximum value of 160 kcal/mole (672 kJ/mole). A pretest heat treatment of 3000F (1922 K) for 30 min (1800 s) resulted in even higher values of activation energy (>600 kcal/mole, 2520 kJ/mole) in this temperature range. The activation energy for the heat-treated columbium (Nb) could not be determined near 0.5TM because of unusual creep curves involving negligible steady-state creep rates and failure at < 5 pct creep strain. It is suggested that the anomalous activation energy values and the unusual creep behavior in this temperature range are caused by dynamic strain aging involving substitutional atom impurities and that this type of strain aging may be in part responsible for the scatter in previously reported values of activation energy for creep of columbium (Nb) near 0.5TM.
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References
Z. S. Basinski:Acta Met, 1957, vol. 5, p. 684.
H. Conrad and H. Wiedersich:Acta Met, 1960, vol. 8, p. 128.
M. J. Hein:Phil. Mag., 1970, vol. 21, p. 1267.
R. L. Fullman, R. P. Correker, and J. C. Fisher:Trans. AIME, 1953, vol. 197, p. 647.
R. Resnick and L. S. Castleman:Trans. TMS-AIME, 1960, vol. 218, p. 307.
T. S. Lundy and F. R. Winslow:Trans. TMS-AIME, 1965, vol. 233, p. 1533.
S. L. Robinson and 0. D. Sherby:Acta Met, 1969, vol. 17, p. 109.
H. Conrad:J. Metals, 1964, vol. 16, p. 582.
J. H. Bechtold, E. T. Wessel, and L. L. France:Refractory Metal Alloys, p. 25, Interscience Publishers, New York, 1961.
B. A. Wilcox:Refractory Metal Alloys, p. 1, Plenum Press, New York, 1968.
P. R. Landon, J. L. Lytton, and J. E. Dorn:Trans. ASM, 1959, vol. 51, p. 900.
N. R. Borch, L. A. Shepard, and J. E. Dorn:Trans. ASM, 1960, vol. 52, p. 494.
D. Walton, L. Shepard, and J. E. Dorn:Trans. TMS-AIME, 1961, vol. 221, p. 458.
J. J. Holmes:J. Nucl. Mater., 1964, vol. 18, p. 133.
G. Brunson and B. Argent:J Inst. Metals, 1962–63, vol. 91, p. 293.
D. P. Gregory and G. H. Rowe:Columbium Metallurgy, AIME Conferences, 1960, vol. 10, p. 309.
J. Stoop and p. Shahenian:High Temperature Refractory Metals, Part 2, AIME Conferences, vol. 34, p. 407, 1966.
J. D. Rawson and B. B. Argent:J. Inst. Metals, 1967, vol. 95, p. 212.
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Klein, M.J., Gulden, M.E. The activation energy for creep of columbium (Niobium). Metall Trans 4, 2175–2180 (1973). https://doi.org/10.1007/BF02643284
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DOI: https://doi.org/10.1007/BF02643284