000190997 001__ 190997
000190997 005__ 20190316235751.0
000190997 0247_ $$2doi$$a10.1007/s11661-013-1911-8
000190997 022__ $$a1073-5623 000190997 02470$$2ISI$$a000326048200028 000190997 037__$$aARTICLE
000190997 245__ $$aDendritic Growth Morphologies in Al-Zn Alloys-Part II: Phase-Field Computations 000190997 269__$$a2013
000190997 260__ $$aNew York$$bSpringer Verlag$$c2013 000190997 300__$$a12
000190997 336__ $$aJournal Articles 000190997 520__$$aIn Part I of this article, the role of the Zn content in the development of solidification microstructures in Al-Zn alloys was investigated experimentally using X-ray tomographic microscopy. The transition region between dendrites found at low Zn content and dendrites found at high Zn content was characterized by textured seaweed-type structures. This Dendrite Orientation Transition (DOT) was explained by the effect of the Zn content on the weak anisotropy of the solid-liquid interfacial energy of Al. In order to further support this interpretation and to elucidate the growth mechanisms of the complex structures that form in the DOT region, a detailed phase-field study exploring anisotropy parameters' space is presented in this paper. For equiaxed growth, our results essentially recapitulate those of Haxhimali et al.[1] in simulations for pure materials. We find distinct regions of the parameter space associated with and dendrites, separated by a region where hyperbranched dendrites are observed. In simulations of directional solidification, we find similar behavior at the extrema, but in this case, the anisotropy parameters corresponding to the hyperbranched region produce textured seaweeds. As noted in the experimental work reported in Part I, these structures are actually dendrites that prefer to grow misaligned with respect to the thermal gradient direction. We also show that in this region, the dendrites grow with a blunted tip that oscillates and splits, resulting in an oriented trunk that continuously emits side branches in other directions. We conclude by making a correlation between the alloy composition and surface energy anisotropy parameters.
000190997 700__ $$aDantzig, J. A.$$uEcole Polytech Fed Lausanne, Lab Simulat Mat, EPFL STI IMX LSMX, Stn 12, CH-1015 Lausanne, Switzerland
000190997 700__ $$0245440$$aDi Napoli, Paolo$$g212998 000190997 700__$$aFriedli, J.
000190997 700__ $$0241586$$aRappaz, M.$$g106186 000190997 773__$$j44A$$k12$$q5532-5543$$tMetallurgical And Materials Transactions A-Physical Metallurgy And Materials Science 000190997 8564_$$s1123941$$uhttps://infoscience.epfl.ch/record/190997/files/Dantzig_etal.pdf$$yPostprint$$zPostprint 000190997 909C0$$0252075$$pLSMX$$xU10337
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000190997 917Z8 $$x101178 000190997 937__$$aEPFL-ARTICLE-190997
000190997 973__ $$aEPFL$$rREVIEWED$$sPUBLISHED 000190997 980__$$aARTICLE