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In situ transmission electron microscopy investigation on 〈c + a〉 slip in Mg

Published online by Cambridge University Press:  11 February 2019

Dalong Zhang Open the ORCID record for Dalong Zhang [Opens in a new window] ,
Lin Jiang ,
Xin Wang ,
Irene J. Beyerlein ,
Andrew M. Minor ,
Julie M. Schoenung ,
Subhash Mahajan  and
Enrique J. Lavernia
Dalong Zhang
Affiliation:
Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, California 92697-2575, USA
Lin Jiang
Affiliation:
Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, California 92697-2575, USA
Xin Wang
Affiliation:
Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, California 92697-2575, USA
Irene J. Beyerlein
Affiliation:
Mechanical Engineering Department, Materials Department, University of California-Santa Barbara, Santa Barbara, California 93106, USA
Andrew M. Minor
Affiliation:
Department of Materials Science and Engineering, University of California-Berkeley, and National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
Julie M. Schoenung
Affiliation:
Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, California 92697-2575, USA
Subhash Mahajan
Affiliation:
Department of Materials Science and Engineering, University of California-Davis, Davis, California 95616, USA
Enrique J. Lavernia*
Affiliation:
Department of Chemical Engineering and Materials Science, University of California-Irvine, Irvine, California 92697-2575, USA
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Recent molecular dynamics simulations revealed that 〈c + a〉 dislocations in Mg were prone to dissociation on the basal plane, thus becoming sessile. Basal dissociation of 〈c + a〉 dislocations is significant because it is a major factor in the limited ductility and high work-hardening in Mg. We report an in situ transmission electron microscopy study of the deformation process using an H-bar-shaped thin foil of Mg single crystal designed to facilitate 〈c + a〉 slip, observe 〈c + a〉 dislocation activity, and establish the validity of the largely immobile 〈c + a〉 dislocations caused by the predicted basal dissociation. In addition, through detailed observations on the fine movement of some 〈c + a〉 dislocations, it was revealed that limited bowing out movement for some non-basal portions of 〈c + a〉 dislocations was possible; under certain circumstances, i.e., through attraction and reaction between two 〈c + a〉 dislocations on the same pyramidal plane, at least portions of the sessile configuration were observed to be reversed into a glissile one.

Keywords

Mgdislocationstransmission electron microscopy
Type
Article
Information
Journal of Materials Research , Volume 34 , Issue 9: Focus Issue: Plasticity and Fracture at the Nanoscales - Advances in in situ Experimentation Techniques Enabling Novel and Extreme Materials/Nanocomposite Design , 14 May 2019 , pp. 1499 - 1508
Copyright
Copyright © Materials Research Society 2019 

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Footnotes

b)

Now at Pacific Northwest National Laboratory.

c)

Now at Materials & Structural Analysis, Thermo Fisher Scientific, Hillsboro, OR, 97124.

References

Price, P.B.: Nonbasal glide in dislocation-free cadmium crystals. II. The $\left( {11\bar{2}2} \right)\left[ {\bar{1}\bar{1}23} \right]$ system. J. Appl. Phys. 32, 1750 (1961).CrossRefGoogle Scholar
Rosenbaum, H.S.: Non-basal slip and twin accommodation in zinc crystals. Acta Metall. 9, 742 (1961).CrossRefGoogle Scholar
Stohr, J.F. and Poirier, J.P.: Etude en microscopie electronique du glissement pyramidal {1122} 〈1123〉 dans le magnesium. Philos. Mag. 25, 1313 (1972).CrossRefGoogle Scholar
Obara, T., Yoshinga, H., and Morozumi, S.: $\left\{ {11\bar{2}2} \right\}$〈1123〉 Slip system in magnesium. Acta Metall. 21, 845 (1973).CrossRefGoogle Scholar
Yoo, M.H.: Slip, twinning, and fracture in hexagonal close-packed metals. Metall. Trans. A 12, 409 (1981).CrossRefGoogle Scholar
Yoo, M.H., Agnew, S.R., Morris, J.R., and Ho, K.M.: Non-basal slip systems in HCP metals and alloys: Source mechanisms. Mater. Sci. Eng., A 319, 87 (2001).CrossRefGoogle Scholar
Agnew, S.R., Horton, J.A., and Yoo, M.H.: Transmission electron microscopy investigation of 〈c + a〉 dislocations in Mg and α-solid solution Mg–Li alloys. Metall. Mater. Trans. A 33, 851 (2002).CrossRefGoogle Scholar
Ando, S., Gotoh, T., and Tonda, H.: Molecular dynamics simulation of 〈c + a〉 dislocation core structure in hexagonal-close-packed metals. Metall. Mater. Trans. A 33, 823 (2002).CrossRefGoogle Scholar
Sandlöbes, S., Friák, M., Neugebauer, J., and Raabe, D.: Basal and non-basal dislocation slip in Mg–Y. Mater. Sci. Eng., A 576, 61 (2013).CrossRefGoogle Scholar
Geng, J., Chisholm, M.F., Mishra, R.K., and Kumar, K.S.: The structure of 〈c + a〉 type dislocation loops in magnesium. Philos. Mag. Lett. 94, 377 (2014).CrossRefGoogle Scholar
Wu, Z. and Curtin, W.A.: The origins of high hardening and low ductility in magnesium. Nature 526, 62 (2015).CrossRefGoogle ScholarPubMed
Buey, D. and Ghazisaeidi, M.: Atomistic simulation of 〈c + a〉 screw dislocation cross-slip in Mg. Scr. Mater. 117, 51 (2016).CrossRefGoogle Scholar
Itakura, M., Kaburaki, H., Yamaguchi, M., and Tsuru, T.: Novel cross-slip mechanism of pyramidal screw dislocations in magnesium. Phys. Rev. Lett. 116, 225501 (2016).CrossRefGoogle ScholarPubMed
Wu, Z. and Curtin, W.A.: Intrinsic structural transitions of the pyramidal I 〈c + a〉 dislocation in magnesium. Scr. Mater. 116, 104 (2016).CrossRefGoogle Scholar
Wu, Z. and Curtin, W.A.: Mechanism and energetics of 〈c + a〉 dislocation cross-slip in hcp metals. Proc. Natl. Acad. Sci. U. S. A. 113(40), 11137–11142 (2016).Google Scholar
Wu, Z., Yin, B., and Curtin, W.A.: Energetics of dislocation transformations in hcp metals. Acta Mater. 119, 203 (2016).CrossRefGoogle Scholar
Xie, K.Y., Alam, Z., Caffee, A., and Hemker, K.J.: Pyramidal I slip in c-axis compressed Mg single crystals. Scr. Mater. 112, 75 (2016).CrossRefGoogle Scholar
Wu, Z., Ahmad, R., Yin, B., Sandlöbes, S., and Curtin, W.A.: Mechanistic origin and prediction of enhanced ductility in magnesium alloys. Science 359, 447 (2018).CrossRefGoogle ScholarPubMed
Tang, Y. and El-Awady, J.A.: Formation and slip of pyramidal dislocations in hexagonal close-packed magnesium single crystals. Acta Mater. 71, 319 (2014).CrossRefGoogle Scholar
Sandlöbes, S., Friák, M., Zaefferer, S., Dick, A., Yi, S., Letzig, D., Pei, Z., Zhu, L.F., Neugebauer, J., and Raabe, D.: The relation between ductility and stacking fault energies in Mg and Mg–Y alloys. Acta Mater. 60, 3011 (2012).CrossRefGoogle Scholar
Agnew, S.R., Capolungo, L., and Calhoun, C.A.: Connections between the basal I1 “growth” fault and 〈c + a〉 dislocations. Acta Mater. 82, 255 (2015).CrossRefGoogle Scholar
Wu, Z., Francis, M.F., and Curtin, W.A.: Magnesium interatomic potential for simulating plasticity and fracture phenomena. Modell. Simul. Mater. Sci. Eng. 23, 015004 (2015).CrossRefGoogle Scholar
Zhiqing, Y., Chisholm, M.F., Duscher, G., Xiuliang, M., and Pennycook, S.J.: Direct observation of dislocation dissociation and Suzuki segregation in a Mg–Zn–Y alloy by aberration-corrected scanning transmission electron microscopy. Acta Mater. 61, 350 (2013).Google Scholar
Geng, J., Chisholm, M.F., Mishra, R.K., and Kumar, K.S.: An electron microscopy study of dislocation structures in Mg single crystals compressed along [0 0 0 1] at room temperature. Philos. Mag. 95, 3910 (2015).CrossRefGoogle Scholar
Ye, J., Mishra, R.K., Sachdev, A.K., and Minor, A.M.: In situ TEM compression testing of Mg and Mg–0.2 wt% Ce single crystals. Scr. Mater. 64, 292 (2011).CrossRefGoogle Scholar
Yu, Q., Qi, L., Chen, K., Mishra, R.K., Li, J., and Minor, A.M.: The nanostructured origin of deformation twinning. Nano Lett. 12, 887 (2012).CrossRefGoogle ScholarPubMed
Bei, H., Lu, Z.P., and George, E.P.: Theoretical strength and the onset of plasticity in bulk metallic glasses investigated by nanoindentation with a spherical indenter. Phys. Rev. Lett. 93, 125504 (2004).CrossRefGoogle ScholarPubMed
Zhu, T., Li, J., Van Vliet, K.J., Ogata, S., Yip, S., and Suresh, S.: Predictive modeling of nanoindentation-induced homogeneous dislocation nucleation in copper. J. Mech. Phys. Solids 52, 691 (2004).CrossRefGoogle Scholar
Mao, W.G., Shen, Y.G., and Lu, C.: Nanoscale elastic–plastic deformation and stress distributions of the C plane of sapphire single crystal during nanoindentation. J. Eur. Ceram. Soc. 31, 1865 (2011).CrossRefGoogle Scholar
Catoor, D., Gao, Y.F., Geng, J., Prasad, M.J.N.V., Herbert, E.G., Kumar, K.S., Pharr, G.M., and George, E.P.: Incipient plasticity and deformation mechanisms in single-crystal Mg during spherical nanoindentation. Acta Mater. 61, 2953 (2013).CrossRefGoogle Scholar
Kwon, J., Brandes, M.C., Sudharshan Phani, P., Pilchak, A.P., Gao, Y.F., George, E.P., Pharr, G.M., and Mills, M.J.: Characterization of deformation anisotropies in an α-Ti alloy by nanoindentation and electron microscopy. Acta Mater. 61, 4743 (2013).CrossRefGoogle Scholar
Shin, J.H., Kim, S.H., Ha, T.K., Oh, K.H., Choi, I.S., and Han, H.N.: Nanoindentation study for deformation twinning of magnesium single crystal. Scr. Mater. 68, 483 (2013).CrossRefGoogle Scholar
Selvarajou, B., Shin, J-H., Ha, T.K., Choi, I-s., Joshi, S.P., and Han, H.N.: Orientation-dependent indentation response of magnesium single crystals: Modeling and experiments. Acta Mater. 81, 358 (2014).CrossRefGoogle Scholar
Partridge, P.G.: The crystallography and deformation modes of hexagonal close-packed metals. Metall. Rev. 12, 169 (1967).Google Scholar
Li, B., Ma, E., and Ramesh, K.T.: Dislocation configurations in an extruded ZK60 magnesium alloy. Metall. Trans. A 39A, 2607 (2008).CrossRefGoogle Scholar
Zhang, D., Wen, H., Kumar, M.A., Chen, F., Zhang, L., Beyerlein, I.J., Schoenung, J.M., Mahajan, S., and Lavernia, E.J.: Yield symmetry and reduced strength differential in Mg–2.5Y alloy. Acta Mater. 120, 75 (2016).CrossRefGoogle Scholar
Zhang, D., Jiang, L., Schoenung, J.M., Mahajan, S., and Lavernia, E.J.: TEM study on relationship between stacking faults and non-basal dislocations in Mg. Philos. Mag. 95, 3823–3844 (2015).CrossRefGoogle Scholar
Hull, D. and Bacon, D.J.: Introduction to Dislocations (Butterworth-Heinemann, Oxford, UK, 2011).Google Scholar
Rodney, D., Ventelon, L., Clouet, E., Pizzagalli, L., and Willaime, F.: Ab initio modeling of dislocation core properties in metals and semiconductors. Acta Mater. 124, 633 (2017).CrossRefGoogle Scholar
Hirth, J.P. and Lothe, J.: Theory of Dislocations, 2nd ed. (John Willey & Sons., New York, 1982).Google Scholar
Hu, Y., Shu, L., Yang, Q., Guo, W., Liaw, P.K., Dahmen, K.A., and Zuo, J-M.: Dislocation avalanche mechanism in slowly compressed high entropy alloy nanopillars. Commun. Phys. 1, 61 (2018).CrossRefGoogle Scholar

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