Microstructural evolution and mechanical properties of Mg95.5Y3Zn1.5 alloy processed by extrusion and ECAP

• Published in: Metals and materials international Vol. 20; no. 2; pp. 285 - 290
• Main Authors: Chen, Bin, Lu, Chen, Lin, Dongliang, Zeng, Xiaoqin
• Format: Journal Article
• Language: English
• Published: Springer The Korean Institute of Metals and Materials 01-03-2014; 대한금속·재료학회
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Engineering Thermodynamics; Heat and Mass Transfer; Machines; Magnetic Materials; Magnetism; Manufacturing; Materials Science; Metallic Materials; Processes; Solid Mechanics; 재료공학; transmission electron microscopy (TEM); equal channel angular pressing (ECAP); alloys; microstructure; extrusion
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-014-2025-6

A Mg
95.5
Y
3
Zn
1.5
alloy processed via a two-step processing route of extrusion plus ECAP has been investigated. It was found that the ECAP processed Mg
95.5
Y
3
Zn
1.5
alloy contained ultrafine grains and exhibited excellent mechanical properties. After ECAP, the average grain size of Mg
95.5
Y
3
Zn
1.5
alloy was refined to about 300 nm. The highest strengths, with yield strength of 444.6 MPa and ultimate tensile strength of 472.7 MPa, were obtained after 1 pass at 623 K. The SAED patterns indicated that the microstructure after ECAP consisted of both high angle and low angle grain boundaries. The fraction of high-angle boundaries increased with increasing numbers of ECAP passes. The Mg
95.5
Y
3
Zn
1.5
alloy contained a high volume fraction of X-Mg
12
ZnY phase due to high yttrium and zinc addition. And, it accelerated the growth and coalescence of cracks during tensile testing, resulting in premature fracture and lower elongation of alloy.