锻压技术

Mg-Gd-Y-Zr合金单向压缩过程中动态再结晶行为研究

英文标题：Dynamic recrystallization behavior during uni-directional compression process of Mg-Gd-Y-Zr alloy

作者：王必正刘楚明油超万迎春

单位：中南大学

分类号：TG319

出版年,卷(期):页码：2019,44(12):146-152

摘要：

利用电子背散射衍射技术（EBSD）研究了Mg-8.3Gd-2.6Y-0.4Zr合金在单向压缩中的动态再结晶行为。结果表明：在475 ℃单向压缩过程中，随着真应变的增加，变形晶粒被不断地拉长和破碎，而动态再结晶在比重提升的同时，其平均晶粒尺寸保持稳定（约为10 μm）；此外，在变形中小角度晶界不断转化成大角度晶界；而在ε=0.4的样品中，变形晶粒从心部到晶界处的取向差角不断增加，并导致再结晶晶粒在其晶界处出现。研究表明，合金再结晶的机制为连续动态再结晶。(0001)面极图显示，再结晶晶粒具有稳定的随机织构类型，并不随应变量的变化而发生改变。这种随机的织构是连续动态再结晶机制和稀土原子对晶界的钉扎共同作用的结果。

The dynamic recrystallization (DRX) behavior during uni-directional compression of Mg-8.3Gd-2.6Y-0.4Zr alloy was investigated by the electron backscattering diffraction(EBSD). The results show that with the increasing of true strain during the uni-directional compression process at 475 ℃, the deformed grains are gradually elongated and broken up, while the fraction of DRXed grains persistently increases without changing their average grain size (about 10 μm). In addition, the low angle boundaries continuously transform into high angle boundaries during deformation, and in the sample with ε=0.4, the orientation difference angle of the deformed grains from the inner to the grain boundary continuously increases, causing the occurrence of recrystallized grains at the grain boundaries. Furthermore, the researches show that the mechanism of DRX is continuous DRX, and the (0001) plane pole figure reveals that the recrystallized grains have a stable random texture type and do not vary with the change of strain, which can be ascribed to the combined effect of the continuous DRX mechanism and the pinning effect of rare earth atoms on grain boundaries.

基金项目：

国家自然科学基金资助项目（51574291，51874367）

王必正（1992-），男，博士研究生 E-mail：csumsewbz_239@163.com 通讯作者：万迎春（1989-），女，博士后，讲师 E-mail：ycwanmse@126.com

参考文献：

［1］Mordike B L, Ebert T. Magnesium: properties-applications-potential
［J］. Materials Science and Engineering: A, 2001, 302(1): 37-45.

［2］Chen Z B, Liu C M, Xiao H C, et al. Effect of rolling passes on the microstructures and mechanical properties of Mg-Gd-Y-Zr alloy sheets
［J］. Materials Science and Engineering: A, 2014, 618: 232-237.

［3］Shahzad M, Wagner L. Influence of extrusion parameters on microstructure and texture developments, and their effects on mechanical properties of the magnesium alloy AZ80
［J］. Materials Science and Engineering: A, 2009, 506(1-2): 141-147.

［4］Wang B, Liu C, Gao Y, et al. Microstructure evolution and mechanical properties of Mg-Gd-Y-Ag-Zr alloy fabricated by multidirectional forging and ageing treatment
［J］. Materials Science and Engineering: A, 2017, 702: 22-28.

［5］Yu H, Park S H, You B S, et al. Effects of extrusion speed on the microstructure and mechanical properties of ZK60 alloys with and without 1 wt% cerium addition
［J］. Materials Science and Engineering: A, 2013, 583: 25-35.

［6］Su Z, Wan L, Sun C, et al. Hot deformation behavior of AZ80 magnesium alloy towards optimization of its hot workability
［J］. Materials Characterization, 2016, 122: 90-97.

［7］Tang L, Liu C, Chen Z, et al. Microstructures and tensile properties of Mg-Gd-Y-Zr alloy during multidirectional forging at 773 K
［J］. Materials & Design, 2013, 50: 587-596.

［8］Xiao H C, Jiang S N, Tang B, et al. Hot deformation and dynamic recrystallization behaviors of Mg-Gd-Y-Zr alloy
［J］. Materials Science and Engineering: A, 2015, 628: 311-318.

［9］Cram D G, Fang X Y, Zurob H S, et al. The effect of solute on discontinuous dynamic recrystallization
［J］. Acta Materialia,2012, 60(18): 6390-6404.

［10］Galiyev A, Kaibyshev R, Gottstein G. Correlation of plastic deformation and dynamic recrystallization in magnesium alloy ZK60
［J］. Acta Materialia, 2001, 49(7): 1199-1207.

［11］Ding H, Liu L, Kamado S, et al. Study of the microstructure, texture and tensile properties of as-extruded AZ91 magnesium alloy
［J］. Journal of alloys and compounds, 2008, 456(1-2): 400-406.

［12］Nodooshan H R J, Liu W, Wu G, et al. Effect of Gd content on microstructure and mechanical properties of Mg-Gd-Y-Zr alloys under peak-aged condition
［J］. Materials Science and Engineering: A, 2014, 615: 79-86.

［13］Wang H, Wang Q D, Boehlert C J, et al. The impression creep behavior and microstructure evolution of cast and cast-then-extruded Mg-10Gd-3Y-0.5 Zr (wt%)
［J］. Materials Science and Engineering: A, 2016, 649: 313-324.

［14］Al-Samman T, Li X. Sheet texture modification in magnesium-based alloys by selective rare earth alloying
［J］. Materials Science and Engineering: A, 2011, 528(10-11): 3809-3822.

［15］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.

［16］Stanford N. Micro-alloying Mg with Y, Ce, Gd and La for texture modification-A comparative study
［J］. Materials Science and Engineering: A, 2010, 527(10-11): 2669-2677.

［17］Stanford N, Sha G, Xia J H, et al. Solute segregation and texture modification in an extruded magnesium alloy containing gadolinium
［J］. Scripta Materialia, 2011, 65(10): 919-921.

［18］Zhou H, Cheng G M, Ma X L, et al. Effect of Ag on interfacial segregation in Mg-Gd-Y-(Ag)-Zr alloy
［J］. Acta Materialia, 2015, 95: 20-29.

［19］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, JIM, 1995, 36(10): 1249-1254.

［20］Xia X, Chen Q, Zhao Z, et al. Microstructure, texture and mechanical properties of coarse-grained Mg-Gd-Y-Nd-Zr alloy processed by multidirectional forging
［J］. Journal of Alloys and Compounds, 2015, 623: 62-68.

［21］Xia X, Chen Q, Zhao Z, et al. Microstructure, texture and mechanical properties of coarse-grained Mg-Gd-Y-Nd-Zr alloy processed by multidirectional forging
［J］. Journal of Alloys and Compounds, 2015, 623: 62-68.

［22］Xia X, Zhang K, Li X, et al. Microstructure and texture of coarse-grained Mg-Gd-Y-Nd-Zr alloy after hot compression
［J］. Materials & Design, 2013, 44: 521-527.

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