Influence of minor additions on Icosahedral Short-Range Order (ISRO) and its consequences on nucleation and solidification growth kinetics in fcc alloys

The present contribution reviews the recent progress related to the influence of Icosahedral Short-Range Order (ISRO) and icosahedral Quasicrystals (i-QC) formation on the solidification of fcc alloys through minor solute element additions. From intensive crystallographic analysis of multi-twinned regions in as-cast Al-based and Au-based fcc alloys, Kurtuldu et al. have shown recently that a so-called "iQC-mediated" nucleation mechanism occurs when a few hundred ppm of Cr and Ir, respectively, are added to the melt [1] [2]. Similarly, it appears that the growth directions of dendrites in Al-Zn:Cr is also influenced by ISRO in the liquid, thus showing an attachment kinetics effect [3]. In a recent contribution, we have shown that iQC-mediated nucleation also occurs in pink gold alloys with Ir-additions, but two additional phenomena at high solidification speed [4]: (i) a spinodal-type decomposition of the liquid, leading to the formation of twinned Cu precipitates in addition to multi-twinned Aurich grains; (ii) a change of the microstructure of the Au-rich grains, from < 100 > dendrites to < 111 > textured cells in the columnar zone.


Published in:
Joint 5Th International Conference On Advances In Solidification Processes (Icasp-5) & 5Th International Symposium On Cutting Edge Of Computer Simulation Of Solidification, Casting And Refining (Csscr-5), 529, 012045
Presented at:
Joint Conference of 5th International Conference on Advances in Solidification Processes (ICASP) and 5th International Symposium on Cutting Edge of Computer Simulation of Solidification, Casting and Refining (CSSCR), Salzburg, AUSTRIA, Jun 17-21, 2019
Year:
Jan 01 2019
Publisher:
Bristol, IOP PUBLISHING LTD
ISSN:
1757-8981
Keywords:
al ; cr ; phase
Note:
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence.
Laboratories:


Note: The status of this file is: Anyone


 Record created 2020-09-09, last modified 2020-09-09

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