Microstructural Evolvement of Al-1.5Si-1.1Mg-0.5Cu Alloy Ingot during Homogenization Treatment

Abstract:

The kinds, morphologies and distributions, enclosed the micro-structural evolvement of Al-1.5Si-1.1Mg-0.5Cu alloy during homogenization treatment were investigated by means of optical microscopy, XRD, SEM/EDS and TEM/EDS. The results show that there were mainly three kinds of morphologically distinct constituents in as-cast Al-1.5Si-1.1Mg-0.5Cu alloy for automotive panels, such as coarse Mg2Si and Al8(FeMn)2Si, and multiphase eutectic structure consisted of AlMgSiFeCu elements, except the α-Al matrix phase. The coarse Mg2Si and Al8(FeMn)2Si were distributed in the α-Al interdentritic regions or at grain boundaries, the former sometimes appears more obvious eutectic characteristics than the later one. The multiphase eutectic products distributed both inside grains with agglomerate aspects and along the α-Al interdentritic regions or at grain boundaries, which is contained with Si and Al2Cu. Coarse binary eutectic structure Mg2Si partly dissolved into matrix and the eutectic characteristics disappeared, whereas Al8(FeMn)2Si changed a little during homogenization. Agglomerate multi-eutectic structures were non-equilibrium products, some of them fully dissolved into matrix and the others partially dissolved and left the discrete blocky Si behind after homogenization.

• Periodical: Materials Science Forum (Volumes 546-549)
• Pages: 1037-1042
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.546-549.1037
• Online since: May 2007
• Authors: Ni Tian, Gang Zhao, Chun Ming Liu, Liang Zuo
• Keywords: Al-Mg-Si-Cu Alloy, Constituents, Eutectic Structures, Homogenization

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