| Autor: |
Zaretsky, E. B., Paris, V., Efremenkov, I., Kalabukhov, S., Hayun, S. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 11/21/2024, Vol. 136 Issue 19, p1-14, 14p |
| Abstrakt: |
The response of polycrystalline nitinol with solely austenite structure was studied in three series of planar impact tests characterized by loading of the nitinol samples of 0.5–10 mm thickness by 1 mm thick aluminum impactor accelerated up to velocities of about 387, 429, and 567 m/s. In all the tests, the velocities of the free surfaces of the samples were monitored by a laser velocity interferometer. It was found that in all three test series, the amplitude of elastic precursor wave, being initially greater than 4 GPa, rapidly decays with the propagation distance down to ∼2.5 GPa, below which the decay is hindered by atomic clusters of the nanometer size. Based on the part of the velocity histories indicating the shock-induced austenite–martensite transformation, the initial, of about 2.5 × 103 s−1, and the maximum, up to 1 × 105 s−1, rates of the transformation were determined. As well, the impact stress slightly greater than 4 GPa was determined as that required for the onset of the B2 → B19′ transformation under shock loading. The unloading parts of the same velocity histories allowed a rough estimate of the fraction of the shock-transformed martensite and the elucidation of the virtually complete reversibility of the transformation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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