Improvement of dynamic compression properties and strengthening mechanism of Mg–Y–Nd–Gd–Zr alloy by pre-twinning.
In: Journal of Materials Science, Jg. 58 (2023-05-30), Heft 20, S. 8515-8534
Online
academicJournal
Zugriff:
The effects of pre-twinning on the microstructure and dynamic compression properties of non-aged and artificially aged Mg–Y–Nd–Gd–Zr alloys were investigated in this study. Previous studies have shown that in the pre-deformed T3 alloy, precompression along the extrusion direction (ED) generates high-density < a > and < c + a > dislocations and deformation twins, such as the 10 1 ¯ 2 < 10 1 ¯ 1 ¯ > extension, the 10 1 ¯ 1 - 10 1 ¯ 2 double, and 10 1 ¯ 1 < 10 1 ¯ 2 ¯ > compression twins at 86°, 38°, and 56°, respectively. In the pre-deformed T8 alloy artificially aged at 200 °C for 12 h, the dislocation density was found to decrease, with β″ (Mg3Y0.85Nd0.15) and β′ (Mg12NdY) precipitates appearing at both ends of the twin boundary. Subsequently, the precipitates extended toward [0001]Mg and [0001]T in the matrix region and the twin, respectively. The orientation relationships (ORs) between the β″ and β′ precipitates and the matrix/twin were determined to be 01 1 ¯ 0 β ″ / / 0001 Mg / T , 2 1 ¯ 1 ¯ 0 β ″ / / 2 1 ¯ 1 ¯ 0 Mg / T and (001)β′//(0001)Mg/T, 2 1 ¯ 1 ¯ 0 β ′ / / 2 1 ¯ 1 ¯ 0 Mg / T , respectively, in contrast to the counterpart ORs between the β″ and β′ precipitates and the matrix/twin in the non-deformed T61 alloy. Evaluation of the dynamic compression properties showed that compared with the compressive yield strength (CYS) of the T61 alloy, that of the T8 alloy considerably increased from 220 to 339 MPa. However, their ultimate compressive strengths (UCSs) of 363 and 360 MPa, respectively, were similar owing to the synergistic effect between the dislocations, the twin boundaries, and the precipitates. These results suggest that the pre-twinning approach should be adopted to improve the strengths of magnesium alloys. [ABSTRACT FROM AUTHOR]
Titel: |
Improvement of dynamic compression properties and strengthening mechanism of Mg–Y–Nd–Gd–Zr alloy by pre-twinning.
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Autor/in / Beteiligte Person: | Chang, Guoqi ; Li, Wei ; Deng, Guisheng ; Liu, Yuandong |
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Zeitschrift: | Journal of Materials Science, Jg. 58 (2023-05-30), Heft 20, S. 8515-8534 |
Veröffentlichung: | 2023 |
Medientyp: | academicJournal |
ISSN: | 0022-2461 (print) |
DOI: | 10.1007/s10853-023-08521-4 |
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