Evolution of Precipitated Phases during Ageing in High Alloyed Mg-Al Based Alloys

Abstract:

The artificial ageing treatments have been performed in the commercial magnesium alloys AZ80 (Mg-8.2Al-0.5Zn) with different grain size in the temperature interval 150-250 °C. The comprehensive microstructure observations through ageing were carried out by light microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction analysis. Solid solution decomposition proceeds in non-deformed materials by two modes of precipitated γ – Mg₁₇Al₁₂ phase: discontinuous (grain boundary) and continuous (intragranular) precipitation. A competitive formation of precipitation is influenced by either initial grain size or applied cold deformation before ageing. The electrical resistivity measurements have allowed evaluating some kinetic parameters of precipitated γ - Mg₁₇Al₁₂ phase. The good agreements of the obtained volume fractions of γ - Mg₁₇Al₁₂ phase after different ageing time by electrical resistivity and a XRD technique were observed.

• Periodical: Materials Science Forum (Volumes 706-709)
• Pages: 1285-1290
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.706-709.1285
• Online since: January 2012
• Authors: Igor Yakubtsov, Marek Niewczas
• Keywords: Aging, Mg Alloy, Precipitation, γ-Mg₁₇Al₁₂ Phase

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