2018 - Sustainable Industrial Processing Summit & Exhibition
4-7 November 2018, Rio Othon Palace, Rio De Janeiro, Brazil
Seven Nobel Laureates have already confirmed their attendance: Prof. Dan Shechtman, Prof. Sir Fraser Stoddart, Prof. Andre Geim, Prof. Thomas Steitz, Prof. Ada Yonath, Prof. Kurt Wüthrich and Prof. Ferid Murad. More than 400 Abstracts Submitted from about 60 Countries.
Abstract Submission
Login

DETAILLED PROGRAM OVERVIEW

Back
    X-ray and Neutron Diffraction for Characterizing Microstructure
    Tamas Ungar1;
    1UNIVERSITY OF MANCHESTER, Manchester, United Kingdom;
    PAPER: 193/SISAM/Keynote (Oral)
    SCHEDULED: 11:20/Wed./Copacabana A (150/1st)



    ABSTRACT:
    Materials performance depends on the microstructure. Different electron microscopy techniques characterize microstructures almost perfectly and comprehensively, but there are still issues hidden from the scrutiny of electron microscopy: residual and internal stresses [1,2]; load partitioning [1-3]; strain fields [4]; very small lattice defects [5]; bulk average quantitative density numbers [6-8]; and others. Diffraction peak broadening or line profile analysis proves to be a valuable tool complementing electron microscopy for characterizing and quantifying these issues [9]. Modern line profile analysis procedures are based on physically modeled profile functions of different microstructural elements [7,9-11]. In a recent development, the Marquard-Levenberg analytical method has been combined with a special statistical Monte-Carlo procedure, providing global optimization of the physical parameters of microstructure properties [12]. We shall cover the correlation between TEM or X-ray determined dislocation densities in plastically deformed single crystals [1,2,6], in high pressure torsion deformed Ta and Nb [13]; the long range internal stresses in dislocation cell-structures [1,2,6,14], lath martensite steels [3], or the planar defect structure in high temperature sintered SiC [15]. It will be shown how the synergy between electron microscopy and line profile analysis adds to a more comprehensive characterization of substructures. The synergy between the two techniques renders a more complete understanding of both the qualitative and quantitative properties of microstructure elements in terms of dislocation types and densities, dipole character of different dislocation arrangements, internal stresses, or planar defect densities [1-15].

    References:
    [1] H. Mughrabi, T. Ungar, W. Kienle and M. Wilkens, Phil. Mag. 53 (1986) 793-813.
    [2] E. Schafler, K. Simon, S. Bernstorff, P. Hanak, G. Tichy and T. Ungar and M. Zehetbauer Acta Mater. 53 (2005) 315-322.
    [3] T. Ungar, S. Harjo, T. Kawasaki, Y. Yomota, G. Ribarik and Z. Shi, Met. Mater. Transact. A48 (2017) 159-167.
    [4] T. Ungar, Ph. A. Dubay, G. Kostorz, Acta Metall. 38 (1990) 2583-2586.
    [5] T. Seymour, P. Frankel, L. Balogh, T. Ungar, S.P. Thompson, D. Jadernas, J. Romero, L. Hallstadius, M.R. Daymond, G. Ribarik and M. Preuss, Acta Mater. 126 (2017) 102-113.
    [6] T. Ungar, H. Mughrabi, D Rönnpagel and M. Wilkens, Acta Metall. 32 (1984) 333-342.
    [7] P. Scardi and M. Leoni, Acta Cryst. A58 (2002) 190-200.
    [8] M. Zehetbauer, T. Ungar, R. Kral, A. Borbely, E. Schafler, B. Ortner, H. Amenitsch and S. Bernstorff, Acta Mater. 47 (1999) 1053-1061.
    [9] G. Ribarik and T. Ungar, Mater. Sci. Eng. A528 (2010) 112-121.
    [10] T. Ungar, I. Dragomir, A. Revesz and A. Borbely, J. Appl. Cryst. 32 (1999) 992-102.
    [11] T. Ungar, J. Gubicza, G. Ribarik and A. Borbely, J. Appl. Cryst. 34 (2001) 298-310.
    [12] G. Ribarik, B. Jóni, and T. Ungar, in preparation.
    [13] B. Jóni, E. Schafler, M. Zehetbauer, G. Tichy and T. Ungar, Acta Mater. 61 (2013) 632-642.
    [14] T. Ungar and M. Zehetbauer, Scripta Mater. 35 (1996) 1467-1473.
    [15] J. Gubicza, S. Nauyoks, L. Balogh, J. Labar, T.W. Zerda and T. Ungar, J. Mater Res. 22 (2007) 1314-1321.