Development of dilute Mg–Zn–Ca–Mn alloy with high performance via extrusion

• Published in: Journal of alloys and compounds Vol. 668; pp. 13 - 21
• Main Authors: Jiang, M.G., Xu, C., Nakata, T., Yan, H., Chen, R.S., Kamado, S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25-05-2016
• Subjects: Dilution; Elongation; Extrusion; Magnesium base alloys; Mechanical properties; Mg–Zn–Ca–Mn alloy; Microstructure; Rare earth metals; Surface layer; Texture; Yield strength; Mechanical properties; Extrusion; Mg–Zn–Ca–Mn alloy; Microstructure; Texture
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2016.01.195

Dilute Mg–0.21Zn–0.30Ca–0.14Mn (wt.%) alloy was newly developed as low-cost wrought Mg alloy. Excellent balance of strength and ductility was achieved via extrusion process by grain refinement and texture modification. The dilute alloy extruded at 300 °C exhibited a tensile yield strength of 307 MPa and an elongation of 20.6% due to a bimodal microstructure consisting of fine dynamically recrystallized (DRXed) grains of ∼2.3 μm and strongly textured coarse unDRXed grains. After extrusion at 350 °C, almost fully DRXed microstructure (DRX fraction of ∼0.96) and significantly weakened basal texture (maximum intensity of 3.2) with rare-earth texture component were achieved, consequently resulting in a high compression/tension yield ratio of ∼0.8 with tensile elongation of 30.0% and tensile yield strength of 164 MPa. Besides, fine spherical Mg2Ca and α-Mn phases dynamically precipitated during extrusion, acting as effective pinning obstacles against the DRXed grain growth.
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•Dilute Mg–Zn–Ca–Mn alloy was newly developed as low-cost wrought Mg alloy.•Excellent balance of strength and ductility was achieved via extrusion process.•Weakened basal texture with RE texture component was formed after almost full DRX.•Fine Mg2Ca and α-Mn phases dynamically precipitated against DRXed grain growth.