Study on microstructure evolution of deformed Mg-Gd-Y-Nd-Zr heat-resistant magnesium alloys after solid solution and ageing

• Published in: Science of sintering Vol. 48; no. 1; pp. 109 - 117
• Main Authors: Jianmin, Yu, Zhimin, Zhang, Xing, Zhang, Fengli, Ren, Yaojin, Wu
• Format: Journal Article
• Language: English
• Published: Beograd International Institute for the Science of Sintering (IISS) 01-01-2016; International Institute for the Science of Sintering, Beograd
• Subjects: ageing treatment; Aging; Deformation; Dynamic recrystallization; Dynamics; Heat treatment; magnesium alloys; Magnesium base alloys; Mg-Gd-Y-Nd-Zr; Microstructure; microstructure evolution; solid solution; Solid solutions
• ISSN: 0350-820X; 1820-7413
• DOI: 10.2298/SOS1601109J

The microstructure evolution of Mg-Gd-Y-Nd-Zr heat-resistant magnesium alloy
after deformation and T5 or T6 treatment were studied. In thermoplastic
deformation, dynamic recrystallization and dynamic precipitation has been
taken place at the same time. The dynamic precipitation reduces the
recrystallization nucleation driving force in the grain; it will prevent to
occur dynamic recrystallization partially. Solid solution temperature was
530oC and hold 4h. Age hardening treatments were performed at 225oC and hold
16h. The alloy showed the comprehensive properties are obviously improved
from T6 to T5 heat treatment. After T5 heat treatment the tensile strength of
alloy increased to 359.3 MPa, increased by around 48.5%; Elongation is
increasing from 5.17% to 6.5%. After peak ageing treatment, the main
precipitation is ?' phase, the precipitation phase have obvious pinning
effect to grain boundary of the alloy, it will prevent the grain growth
ageing for a long-time. At the same time, strengthening role of precipitate
phase make its strength increased significantly.
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