| タイトル | Long-time creep behavior of the niobium alloy C-103 |
| 本文（外部サイト） | http://hdl.handle.net/2060/19800025047 |
| 著者（英） | Klopp, W. D.; Titran, R. H. |
| 著者所属（英） | NASA Lewis Research Center |
| 発行日 | 1980-10-01 |
| 言語 | eng |
| 内容記述 | The creep behavior of C-103 was studied as a function of stress, temperature, and grain size for test times to 19000 hr. Over the temperature range 827 to 1204 C and the stress range 6.89 to 138 MPa, only tertiary (accelerating) creep was observed. The creep strain epsilon can be related to time t by an exponential relation epsilon = epsilon(0) + K e raised to power (st) - 1), where epsilon (0) is initial creep strain, K is the tertiary creep strain parameter, and s is the tertiary creep rate parameter. The observed stress exponent 2.87 is similar to the three power law generally observed for secondary (linear) creep of Class I solid solutions. The apparent activation energy 374 kj/g mol is close to that observed for self diffusion of pure niobium. The initial tertiary creep rate was slightly faster for fine grained than for coarse-grained material. The strain parameter K can be expressed as a combination of power functions of stress and grain size and an exponential function of temperature. Strain time curves generated by using calculated values for K and s showed reasonable agreement with observed curves to strains of at least 4 percent. The time to 1 percent strain was related to stress, temperature, and grain size in a similar manner as the initial tertiary creep rate. |
| NASA分類 | METALLIC MATERIALS |
| レポートNO | 80N33555
NASA-TP-1727
E-224 |
| 権利 | No Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/171062 |
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