Acta Metallurgica Sinica (English Letters) ›› 2014, Vol. 27 ›› Issue (4): 677-681.DOI: 10.1007/s40195-014-0092-9

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Twinning Behaviour in the Intermetallic Compound Al18Cr2Mg3

Maohua Li1(), Yanqing Yang1, Ming Han1, Wei Zhang1, Bin Huang1, Xian Luo1, Jigang Ru2   

  1. 1. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an, 710072, China
    2. Beijing Institute of Aeronautical Materials, Beijing, 100095, China
  • Received:2013-11-22 Revised:2014-02-16 Online:2014-08-25 Published:2014-10-16

Abstract:

The twinning in the intermetallic compound Al18Cr2Mg3 was observed and identified by transmission electron microscopy. The geometric description of the twinning in Al18Cr2Mg3 with 184 atoms per unit cell was investigated at atomic level. The classical theory of deformation twinning states that the net atomic displacements are divided into shear and shuffles during twinning. Based on the theory and the hypothesis of full mirror reflection symmetry, the displacement and angle of shuffle were calculated for each atom. The geometric calculation results show that all of the atoms in single crystal Al18Cr2Mg3 have to shuffle. Moreover, the calculation results can be divided into 22 groups, which do not show obvious regularity.

Key words: Intermetallic compound, Al18Cr2Mg3, Twinning, Shear, Shuffle