Applied Microscopy

  • 제45권4호
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  • Pages.230-235
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  • 2015
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  • 2287-5123(pISSN)
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  • 2287-4445(eISSN)
한국현미경학회 (Korean Society of Microscopy)
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Crystallography Analysis of the β-Mg17Al12 Precipitates by the Secondary Constrained Coincident Site Lattice Model

  • Huang, Xuefei (College of Materials Science and Engineering, Sichuan University) ;
  • Huang, Weigang (College of Materials Science and Engineering, Sichuan University)
  • 투고 : 2015.12.04
  • 심사 : 2015.12.07
  • 발행 : 2015.12.30
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초록

Crystallographic models are effective tools to interpret, calculate and even to predict the preferred crystallographic morphologies of precipitates in various precipitation systems. The present study gives an introduction on the recently developed secondary constrained coincident site lattice (II-CCSL) model. Using the II-CCSL model, the interface matching condition of the ${\beta}-Mg_{17}Al_{12}$ precipitates with ${\alpha}-Mg$ matrix in an aged AZ91 alloy has been analyzed to rationalize the morphologies of the precipitates. The results show that the characteristic crystallographic features of the observed ${\beta}-Mg_{17}Al_{12}$ precipitates, i.e., the habit plane of the ${\beta}-Mg_{17}Al_{12}$ lath with a Burgers orientation relationship (OR) and the growth direction of the ${\beta}-Mg_{17}Al_{12}$ with a Crawley OR exhibit a better lattice matching degree than their vicinal orientations. Moreover, the Crawley OR is preferred to the Burgers OR due to a better lattice match.

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참고문헌

  1. Bollmann W (1982) Crystal Lattices, Interfaces, Matrices (Bollmann, Geneva).
  2. Bonnet R and Durand F (1975) Study of intercrystalline boundaries in terms of the coincidence lattice concept. Phil. Mag. 32, 997-1006. https://doi.org/10.1080/14786437508221668
  3. Celotto S (2000) TEM study of continuous precipitation in Mg-9 wt%Al-1 wt%Zn alloy. Acta Mater. 48, 1775-1787. https://doi.org/10.1016/S1359-6454(00)00004-5
  4. Dahmen U (1981) The role of the invariant line in the search for an optimum interphase boundary by O-lattice theory. Scripta Metall. 15, 77-81. https://doi.org/10.1016/0036-9748(81)90140-X
  5. Dahmen U, Ferguson P, and Westmacott K H (1984) Invariant line strain and needle-precipitate growth directions in Fe-Cu. Acta Metall. 32, 803-810. https://doi.org/10.1016/0001-6160(84)90153-6
  6. Duly D, Zhang W Z, and Audier M (1995) High-resolution electron microscopy observations of the interface structure of continuous precipitates in a Mg-Al alloy and interpretation with the O-lattice theory. Phil. Mag. A 71, 187-204. https://doi.org/10.1080/01418619508242964
  7. Huang X F, Shi Z Z, and Zhang W Z (2014) Transmission electron microscopy investigation and interpretation of the morphology and interfacial structure of the ${\varepsilon}^{'}$-Mg54Ag17 precipitates in an Mg-Sn-Mn-Ag-Zn alloy. J Appl. Crystallogr. 47, 1676-1687. https://doi.org/10.1107/S1600576714018913
  8. Kelly P M and Zhang M X (1999) Edge-to-edge matching: a new approach to the morphology and crystallography of precipitates. Mater. Forum 23, 41-62.
  9. Nie J F (2003) Effects of precipitate shape and orientation on dispersion strengthening in magnesium alloys. Scripta Mater. 48, 1009-1015. https://doi.org/10.1016/S1359-6462(02)00497-9
  10. Nie J F and Muddle B C (1998) Microstructural design of high-strength aluminum alloys. J. Phase Equilib. 19, 543-551. https://doi.org/10.1361/105497198770341734
  11. Shi Z Z, Dai F Z, Zhang M, Gu X F, and Zhang W Z (2013) Secondary coincidence site lattice model for truncated triangular ${\beta}$-Mg2Sn precipitates in a Mg-Sn-based alloy. Metall. Mater. Trans. A 44, 1-9.
  12. Shi Z Z and Zhang W Z (2011) Interpretation of crystallographic morphologies of precipitates in Mg alloys with a secondary CCSL model. Mater. Sci. Forum 686, 192-196. https://doi.org/10.4028/www.scientific.net/MSF.686.192
  13. Yang X P and Zhang W Z (2012) A systematic analysis of good matching sites between two lattices. Sci. China Technol. Sci. 55, 1343-1352. https://doi.org/10.1007/s11431-012-4763-3
  14. Ye F and Zhang W Z (2002) Coincidence structures of interfacial steps and secondary misfit dislocations in the habit plane between Widmanstatten cementite and austenite. Acta Mater. 50, 2761-2777. https://doi.org/10.1016/S1359-6454(02)00077-0
  15. Zhang M X and Kelly P M (2005) Edge-to-edge matching and its applications: part I. Application to the simple HCP/BCC system. Acta Mater. 53, 1073-1084. https://doi.org/10.1016/j.actamat.2004.11.007
  16. Zhang W Z and Purdy G R (1993) O-lattice analyses of interfacial misfit. I. General considerations. Phil. Mag. A 68, 279-290. https://doi.org/10.1080/01418619308221205
  17. Zhang W Z and Weatherly G (2005) On the crystallography of precipitation. Prog. Mater. Sci. 50, 181-292. https://doi.org/10.1016/j.pmatsci.2004.04.002
  18. Zhou J P, Zhao D S, Zheng O, Wang J B, Xiong D X, Sun Z F, Gui J N, and Wang R H (2009) High-resolution electron microscopy observations of continuous precipitates with Pitsch-Schrader orientation relationship in an Mg-Al based alloy and interpretation with the O-lattice theory. Micron 40, 906-910. https://doi.org/10.1016/j.micron.2009.05.008