Enhanced strength and ductility of AZ80 Mg alloys by spray forming and ECAP

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:670

Article

Tang, Lingling¹  Zhao, Yonghao¹  Islamgaliev, R. K.²  Tsao, Chi Y. A.³  Valiev, R. Z.^2,4  Lavernia, E. J.⁵  Zhu, Y. T.^1,6 

[1] Nanjing Univ Sci & Technol, Sch Mat Sci & Engn, Nano Struct Mat Ctr, Nanjing 210094, Jiangsu, Peoples R China

[2] Ufa State Aviat Tech Univ, Inst Phys Adv Mat, 12K Marx St, Ufa, Russia

[3] Natl Cheng Kung Univ, Dept Mat Sci & Engn, 1 Ta Hsue Rd, Tainan 701, Taiwan

[4] St Petersburg State Univ, Lab Mech Bulk Nanomat, 28 Univ Sky Prospekt, St Petersburg 198504, Russia

[5] Univ Calif Irvine, Dept Chem Engn & Mat Sci, Irvine, CA 92697 USA

[6] North Carolina State Univ, Dept Mat Sci & Engn, Box 7907, Raleigh, NC 27695 USA

关键词: Spray forming;    ECAP;    Strengthening;    Deformation mechanisms;    Ultra-fine grains;   

DOI  :  10.1016/j.msea.2016.06.031

来源: Elsevier

【 摘 要 】

The relatively low strength and poor ductility of conventional AZ80 Mg alloys have been attributed to the limited number of independent slip systems, in combination with the formation of fragile eutectic beta-Mg17Al12 networks at grain boundaries. In an effort to overcome these limitations, spray forming followed by equal channel angular pressing (ECAP) was employed to obtain a unique bi-modal microstructure: coarse grains were separated and surrounded by deformation networks consisting of ultrafine-grained Mg with an average grain size of 0.6 mu m and ellipsoidal shaped beta-Mg17Al12 particles with sizes of 200-300 nm. Tensile tests revealed the advantage of this structure: a yield strength of 235 MPa combined with an elongation to failure of 14%; the values are significantly higher than those of their conventional counterparts (100 MPa-12%, and 140 MPa-5%). The underlying strengthening and deformation mechanisms of this particular microstructure are discussed and analyzed. (C) 2016 Elsevier B.V. All rights reserved.

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