On the Plasticity and Deformation Mechanisms in Magnesium Crystals
This work presents an overview of the mechanical response and microstructure evolution of specifically oriented pure magnesium single crystals under plane strain compression at room temperature. Crystals of ‘hard’ orientations compressed along the <i>c</i>-axis exhibited limited room tem...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-03-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/13/4/640 |
| _version_ | 1797604332209700864 |
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| author | Konstantin D. Molodov Talal Al-Samman Dmitri A. Molodov |
| author_facet | Konstantin D. Molodov Talal Al-Samman Dmitri A. Molodov |
| author_sort | Konstantin D. Molodov |
| collection | DOAJ |
| description | This work presents an overview of the mechanical response and microstructure evolution of specifically oriented pure magnesium single crystals under plane strain compression at room temperature. Crystals of ‘hard’ orientations compressed along the <i>c</i>-axis exhibited limited room temperature ductility, although pyramidal ⟨c + a⟩ slip was readily activated, fracturing along crystallographic <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>11</mn><mover accent="true"><mn>2</mn><mo>¯</mo></mover><mn>4</mn></mrow></mfenced></mrow></semantics></math></inline-formula> planes as a result of highly localized shear. Profuse <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> extension twinning was the primary mode of incipient deformation in the case of orientations favorably aligned for <i>c</i>-axis extension. In both cases of compression along ⟨<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>11</mn><mover accent="true"><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>⟩ and ⟨<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>⟩ directions, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> extension twins completely converted the starting orientations into twin orientations; the subsequent deformation behavior of the differently oriented crystals, however, was remarkably different. The formation of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> extension twins could not be prevented by the channel-die constraints when <i>c</i>-axis extension was confined. The presence of high angle grain boundaries and, in particular, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> twin boundaries was found to be a prerequisite for the activation of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>1</mn></mrow></mfenced></mrow></semantics></math></inline-formula> contraction twinning by providing nucleation sites for the latter. Prismatic slip was not found to operate at room temperature in the case of starting orientations most favorably aligned for prismatic slip; instead, cooperative <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> extension and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>1</mn></mrow></mfenced></mrow></semantics></math></inline-formula> contraction twinning was activated. A two-stage work hardening behavior was observed in ‘soft’ Mg crystals aligned for single or coplanar basal slip. The higher work hardening in the second stage was attributed to changes in the microstructure rather than the interaction of primary dislocations with forest dislocations. |
| first_indexed | 2024-03-11T04:44:58Z |
| format | Article |
| id | doaj.art-b5755fdf72a24c1b87cc5af33dee6bb9 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-11T04:44:58Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-b5755fdf72a24c1b87cc5af33dee6bb92023-11-17T20:25:32ZengMDPI AGMetals2075-47012023-03-0113464010.3390/met13040640On the Plasticity and Deformation Mechanisms in Magnesium CrystalsKonstantin D. Molodov0Talal Al-Samman1Dmitri A. Molodov2Department of Materials and Process Development, Salzgitter Mannesmann Forschung GmbH, Eisenhüttenstr. 99, 38239 Salzgitter, GermanyInstitute for Physical Metallurgy and Materials Physics, RWTH Aachen University, 52056 Aachen, GermanyInstitute for Physical Metallurgy and Materials Physics, RWTH Aachen University, 52056 Aachen, GermanyThis work presents an overview of the mechanical response and microstructure evolution of specifically oriented pure magnesium single crystals under plane strain compression at room temperature. Crystals of ‘hard’ orientations compressed along the <i>c</i>-axis exhibited limited room temperature ductility, although pyramidal ⟨c + a⟩ slip was readily activated, fracturing along crystallographic <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>11</mn><mover accent="true"><mn>2</mn><mo>¯</mo></mover><mn>4</mn></mrow></mfenced></mrow></semantics></math></inline-formula> planes as a result of highly localized shear. Profuse <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> extension twinning was the primary mode of incipient deformation in the case of orientations favorably aligned for <i>c</i>-axis extension. In both cases of compression along ⟨<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>11</mn><mover accent="true"><mn>2</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>⟩ and ⟨<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>0</mn></mrow></semantics></math></inline-formula>⟩ directions, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> extension twins completely converted the starting orientations into twin orientations; the subsequent deformation behavior of the differently oriented crystals, however, was remarkably different. The formation of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> extension twins could not be prevented by the channel-die constraints when <i>c</i>-axis extension was confined. The presence of high angle grain boundaries and, in particular, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> twin boundaries was found to be a prerequisite for the activation of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>1</mn></mrow></mfenced></mrow></semantics></math></inline-formula> contraction twinning by providing nucleation sites for the latter. Prismatic slip was not found to operate at room temperature in the case of starting orientations most favorably aligned for prismatic slip; instead, cooperative <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></mfenced></mrow></semantics></math></inline-formula> extension and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mfenced close="}" open="{"><mrow><mn>10</mn><mover accent="true"><mn>1</mn><mo>¯</mo></mover><mn>1</mn></mrow></mfenced></mrow></semantics></math></inline-formula> contraction twinning was activated. A two-stage work hardening behavior was observed in ‘soft’ Mg crystals aligned for single or coplanar basal slip. The higher work hardening in the second stage was attributed to changes in the microstructure rather than the interaction of primary dislocations with forest dislocations.https://www.mdpi.com/2075-4701/13/4/640magnesiumsingle crystaldeformation twinningplasticity |
| spellingShingle | Konstantin D. Molodov Talal Al-Samman Dmitri A. Molodov On the Plasticity and Deformation Mechanisms in Magnesium Crystals Metals magnesium single crystal deformation twinning plasticity |
| title | On the Plasticity and Deformation Mechanisms in Magnesium Crystals |
| title_full | On the Plasticity and Deformation Mechanisms in Magnesium Crystals |
| title_fullStr | On the Plasticity and Deformation Mechanisms in Magnesium Crystals |
| title_full_unstemmed | On the Plasticity and Deformation Mechanisms in Magnesium Crystals |
| title_short | On the Plasticity and Deformation Mechanisms in Magnesium Crystals |
| title_sort | on the plasticity and deformation mechanisms in magnesium crystals |
| topic | magnesium single crystal deformation twinning plasticity |
| url | https://www.mdpi.com/2075-4701/13/4/640 |
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