锻压技术

应变量对锻造Mg-Gd-Y-Zn-Zr合金显微组织和力学性能的影响

英文标题：Influence of strain on microstructure and mechanical properties for forged Mg-Gd-Y-Zn-Zr alloy

作者：刘运峰刘楚明高永浩蒋树农万迎春

单位：中南大学

分类号：TG146.22

出版年,卷(期):页码：2019,44(4):145-150

摘要：

采用多向锻造工艺成功制备出应变量分别为1.5和2.1的两个Mg-Gd-Y-Zn-Zr合金样品，并利用光学显微分析、扫描电子显微分析、XRD宏观织构测量以及力学性能测试等手段，着重研究了不同应变量对锻造样品显微组织和力学性能的影响。结果表明：随着应变量从1.5增加至2.1，样品不同区域的组织都因再结晶体积分数的提高而得到明显细化，但其平均再结晶晶粒尺寸一直保持在2.6 μm左右，与样品应变量和区域无关；应变量为2.1时的样品心部具有最高的综合力学性能，其屈服强度、抗拉强度和伸长率分别为263 MPa、346 MPa和18.6%，其优异的综合力学性能应该归功于大应变导致的晶粒细化和随机晶体取向的共同作用。

Two Mg-Gd-Y-Zn-Zr samples with strain of 1.5 and 2.1 were successfully fabricated by multi-direction forging process, and the influences of different strains on the microstructure and mechanical properties of forging samples were investigated by the optical microscopy, scanning electron microscopy, XRD macrotexture measurement and mechanical property test. The results show that with the increasing of strain from 1.5 to 2.1, the microstructure in different regions of sample is refined to a large extent due to the increase of recrystallization volume fraction. However, the average size of recrystallization grains in such microstructure is kept around 2.6 μm independent of strain and region of sample. Furthermore, the central part of sample with strain of 2.1 occupies the highest comprehensive mechanical properties with the yield strength of 263 MPa, the tensile strength of 346 MPa and the elongation of 18.6%, respectively, and its remarkable mechanical properties can be ascribed to the comprehensive effect of grain refinement and random crystal orientation resulted from the high strain.

基金项目：

国家自然科学基金资助项目（51574291）；中南大学研究生自主探索创新项目(2018zzts485)

刘运峰（1992-），男，硕士研究生 E-mail：15673109789@163.com 通讯作者：刘楚明（1960-），博士，教授，博士生导师 E-mail：cmliu803@sina.com

参考文献：

[1]Wang H, Wang Q D, Yin D D, et al. Tensile creep behavior and microstructure evolution of extruded Mg-10Gd-3Y-0.5Zr (wt%) alloy [J]. Materials Science and Engineering: A, 2013, 578:150-159.

[2]Smola B, Stulíková I, Buch Von F, et al. Structural aspects of high performance Mg alloys design [J]. Materials Science and Engineering: A, 2002, 324(1-2):113-117.

[3]Wang J, Meng J, Zhang D P, et al. Effect of Y for enhanced age hardening response and mechanical properties of Mg-Gd-Y-Zr alloys [J]. Materials Science and Engineering: A, 2007, 456(1-2): 78-84.

[4]Lu F M, Ma A B, Jiang J H, et al. Enhanced mechanical properties and rolling formability of fine-grained Mg-Gd-Zn-Zr alloy produced by equal-channel angular pressing [J]. Journal of Alloys and Compounds, 2015, 643:28-33.

[5]Xu C, Nakata T, Qiao X G, et al. Effect of extrusion parameters on microstructure and mechanical properties of Mg-7.5Gd-2.5Y-3.5Zn-0.9Ca-0.4Zr (wt%) alloy [J]. Materials Science and Engineering: A, 2017, 685:159-167.

[6]Xu C, Zheng M Y, Xu S W, et al. Improving strength and ductility of Mg-Gd-Y-Zn-Zr alloy simultaneously via extrusion, hot rolling and ageing [J]. Materials Science and Engineering: A, 2015, 643:137-141.

[7]Valiev R Z, Islamgaliev R K, Alexandrov I V. Bulk nanostructured materials from severe plastic deformation [J]. Progress in Materials Science, 2000, 45(2):103-189.

[8]Xing J, Soda H, Yang X Y, et al. Ultra-fine grain development in an AZ31 magnesium alloy during multi-directional forging under decreasing temperature conditions [J]. Materials Transactions, 2005, 46(7):1646-1650.

[9]Miura H, Yu G, Yang X. Multi-directional forging of AZ61 Mg alloy under decreasing temperature conditions and improvement of its mechanical properties [J]. Materials Science and Engineering: A, 2011, 528(22-23):6981-6992.

[10]Guo Q, Yan H G, Chen Z H, et al. Grain refinement in as-cast AZ80 Mg alloy under large strain deformation [J]. Materials Characterization, 2007, 58(2):162-167.

[11]Huang H, Zhang J. Microstructure and mechanical properties of AZ31 magnesium alloy processed by multi-directional forging at different temperatures [J]. Materials Science and Engineering: A, 2016, 674:52-58.

[12]Jiang M G, Yan H, Chen R S. Microstructure, texture and mechanical properties in an as-cast AZ61 Mg alloy during multi-directional impact forging and subsequent heat treatment [J]. Materials & Design, 2015, 87: 891-900.

[13]Li J Q, Liu J, Cui Z S. Microstructures and mechanical properties of AZ61 magnesium alloy after isothermal multidirectional forging with increasing strain rate [J]. Materials Science and Engineering: A, 2015, 643: 32-36.

[14]Zhang S, Yuan G Y, Lu C, et al. The relationship between (Mg,Zn)3RE phase and 14H-LPSO phase in Mg-Gd-Y-Zn-Zr alloys solidified at different cooling rates [J]. Journal of Alloys and Compounds, 2011, 509: 3515-3521.

[15]Xu C, Zheng M Y, Wu K, et al. Effect of cooling rate on the microstructure evolution and mechanical properties of homogenized Mg-Gd-Y-Zn-Zr alloy [J]. Materials Science and Engineering: A, 2013, 559:364-370.

[16]Mabuchi M, Kubota K, Higashi K. New recycling process by extrusion for machined chips of AZ91 magnesium and mechanical properties of extruded bars [J]. Materials Transactions, 1995, 36(10):1249-1254.

[17]Hadorn J P, Sasaki T T, Nakata T, et al. Solute clustering and grain boundary segregation in extruded dilute Mg-Gd alloys [J]. Scripta Materialia, 2014, 93:28-31.

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