The effect of different cooling rates (2.7, 5.5, 17.1, and 57.5℃/s) on the solidification parameters, microstructure, and mechanical properties of Al?15Mg2Si composites was studied. The results showed that a high cooling rate refined the Mg2Si particles and changed their morphology to more compacted forms with less microcracking tendency. The average radius and fraction of primary Mg2Si particles de-creased from 20 μm and 13.5％ to about 10 μm and 7.3％, respectively, as the cooling rate increased from 2.7 to 57.5℃/s. Increasing the cool-ing rate also improved the distribution of microconstituents and decreased the grain size and volume fraction of micropores. The mechanical properties results revealed that augmenting the cooling rate from 2.7 to about 57.5℃/s increased the hardness and quality index by 25％ and 245％, respectively. The high cooling rate also changed the fracture mechanism from a brittle-dominated mode to a high-energy ductile mode comprising extensive dimpled zones.

E.Safary;R.Taghiabadi;M.H.Ghoncheh

Department of Materials Science and Metallurgy,Imam Khomeini International University,Qazvin,Iran;Department of Mechanical Engineering,University of New Brunswick,Fredericton,NB,Canada

矿物冶金与材料学报

[1]E.Safary;R.Taghiabadi;M.H.Ghoncheh-.Mechanical properties of Al–15Mg2Si composites prepared under different solidification cooling rates)[J].矿物冶金与材料学报,2022(06):1249-1260

15Mg2Si,microconstituents

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