High strength Mg₉₄Zn_2.4Y_3.6 alloy with long period stacking ordered structure prepared by near-rapid solidification technology

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• 作者：J. Zhu^a ; J.B. Chen^a ; T. Liu^a ; J.X. Liu^b ; W.Y. Wang^c ; Z.K. Liu^c ; X.D. Hui^a ; ^{xdhui@ustb.edu.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Mg&ndash ; Zn&ndash ; Y alloy ; Long period stacking ordering ; Near-rapid solidification ; Mechanical properties
• 刊名：Materials Science & Engineering A
• 出版年：2017
• 出版时间：2 January 2017
• 年：2017
• 卷：679
• 期：Complete
• 页码：476-483
• 全文大小：2580 K

文摘

To obtain high strength for near-rapid solidification (NRS) magnesium alloys, the microstructures and mechanical properties of the Mg₉₄Zn_2.4Y_3.6 (at%) alloys, which were prepared by ordinary and injection copper mold casting (ICMC), respectively, were investigated comprehensively. It has been shown that the microstructure of ICMC Mg₉₄Zn_2.4Y_3.6 alloy possesses the far-away-from equilibrium feature of NRS materials, which is composed of refined α-Mg grains with supersaturated Y and Zn, fine network-like long-period stacking-order (LPSO) phases and a few of Mg₂₄Y₅ particles. The interface between LPSO phase and α-Mg matrix is semi-coherent with the orientation relationship of [0002]_α//[11$\overline{\text{2}}$0]_LPSO, (10$\overline{\text{1}}$0)_α//(0002_)LPSO. The ICMC alloy exhibits enhanced mechanical properties with the ultimate tensile strength and elongation up to 355 MPa and 7% at room temperature, respectively, and with the ultimate tensile strength of 302 MPa at 150 °C. It can be concluded that the strengthening mechanisms of this ICMC alloy are attributed to the grain refinement, the solid solution effect, the secondary phase strengthening and the crystalline boundaries strengthening.