New Metallographic Method for Estimation of Ordering and Lattice Parameter in Ternary Eutectic Systems

Springer Science and Business Media LLC - Tập 2 - Trang 140-147 - 2013
A. Dennstedt1, L. Ratke1, A. Choudhury2, B. Nestler2
1Institut für Materialphysik im Weltraum, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Cologne, Germany
2Institut für Angewandte Materialien, Karlsruhe Institut für Technologie, Karlsruhe, Germany

Tóm tắt

Ternary eutectics develop a rich variety of microstructures depending on the solidification conditions. This article describes a new procedure to analyze the three-phase arrangement in metallographic sections following solidification; this method provides a clear definition of both the interphase spacing and the degree of ordering. Distance and angle between the phase areas are calculated after determination of the centers of mass for each phase area. A polar plot of these data allows an easy determination of the spacing and the order. The new method is discussed with both experimental as well as simulated microstructure images. It is first tested on artificial phase arrangements, which are fully ordered, semi-ordered, or random.

Tài liệu tham khảo

U. Hecht, L. Gránásy, T. Pusztai, B. Böttger, M. Apel, V. Witusiewicz, L. Ratke, J. De Wilde, L. Froyen, D. Camel, B. Drevet, G. Faivre, S.G. Fries, B. Legendre, S. Rex, Multiphase solidification in multicomponent alloys. Mater. Sci. Eng. R 46(1–2), 1–49 (2004) D. Lewis, S. Allen, M. Notis, A. Scotch, Determination of the eutectic structure in the Ag–Cu–Sn system. J. Electron. Mater. 31(2), 161–167 (2002) A. Genau, L. Ratke, Morphological characterization of the Al–Ag–Cu ternary eutectic. Int. J. Mater. Res. 103(4), 469–475 (2012) V. Witusiewicz, U. Hecht, S. Fries, S. Rex, The Ag–Al–Cu system II. A thermodynamic evaluation of the ternary system. J. Alloys Compd. 387(1–2), 217–227 (2005) K. Jackson, J. Hunt, Lamellar and rod eutectic growth. Trans. Metall. Soc. AIME 236, 1129–1142 (1966) T. Himemiya, T. Umeda, Three-phase planar eutectic growth models for a ternary eutectic system. Mater. Trans. JIM 40(7), 665–674 (1999) D.G. McCartney, R.M. Jordan, J.D. Hunt, The structures expected in a simple ternary eutectic system: part II. The Al–Ag–Cu ternary system. Metall. Trans. A 11(8), 1251–1257 (1980) A. Dennstedt, L. Ratke, Microstructures of directionally solidified Al–Ag–Cu ternary eutectics. Trans. Indian Inst. Met. 65(6), 777–782 (2012) J. Alkemper, S. Sous, S. Stöcker, L. Ratke, Directional solidification in an aerogel furnace with high resolution optical temperature measurements. J. Cryst. Growth 191(1–2), 252–260 (1998) A. Choudhury, M. Plapp, B. Nestler, Theoretical and numerical study of lamellar eutectic three-phase growth in ternary alloys. Phys. Rev. E (2011). doi:10.1103/PhysRevE.83.051608 analySIS pro, Olympus Soft Imaging Solutions GmbH (1986–2007). http://www.olympus-sis.com. Accessed 5 Feb 2013 http://www.gnu.org/software/octave/. Accessed 5 Feb 2013 S. Ahrweiler, L. Ratke, J. Lacaze, Microsegregation and microstructural features of directionally solidified AlSi and AlSiMg alloys. Adv. Eng. Mater. 5, 17–23 (2003)