The microstructure and mechanical properties of Mg-3Al-3RE alloys

• Published in: Journal of alloys and compounds Vol. 465; no. 1; pp. 412 - 416
• Main Authors: Tian, X., Wang, L.M., Wang, J.L., Liu, Y.B., An, J., Cao, Z.Y.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 06-10-2008; Elsevier
• Subjects: Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Exact sciences and technology; Mechanical and acoustical properties of condensed matter; Mechanical properties (structural characterization); Mechanical properties of solids; Metallography (phenomena); Metals and alloys (types of material); Microstructure (structural characterization); Physics; Rare earth alloys and compounds (types of material); Metals and alloys (types of material); Mechanical properties (structural characterization); Rare earth alloys and compounds (types of material); Metallography (phenomena); Microstructure (structural characterization); Grain size; Ultimate strength method; Mechanical properties; Metallography; Casting; Magnesium base alloys; Ductile fracture; Microstructure; Fractography
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2007.10.100

The Mg-3Al-3RE alloys (RE, the cerium-rich or the yttrium-rich misch metal) were smelted in a resistance furnace under the protective flux from the Mg-RE master alloys and pure magnesium ingots. The microstructure and mechanical properties of samples prepared by steel mould casting method were investigated. Results show that the main phases of the alloys are α-Mg, Mg
17Al
12 and Al-RE compounds, and the grain size reduced with the increasing content of the cerium-rich misch metal. Mg-3Al-2Ymm-1Cemm (Ymm, the yttrium-rich misch metal; Cemm, the Cerium-rich misch metal) exhibited the highest mechanical properties, that is UTS
=
201
MPa and YS
=
75
MPa, and
ɛ
=
8.2% at room temperature; UTS
=
146
MPa, and YS
=
70
MPa,
ɛ
=
18.2% at the temperature of 150
°C, respectively. Fracture surface analysis revealed that the Mg-3Al-2Ymm-1Cemm alloy has a mixed fracture feature at room temperature but ductile fracture at elevated temperature (150
°C).