采用光学显微镜(OM)、扫描电镜(SEM)结合电子背散射衍射(EBSD)、X射线衍射仪(XRD)及拉伸试验机对不同拉伸应变量下A731镁合金挤压板的显微组织、微观织构、宏观织构及力学性能进行了观察.结果表明:在拉伸变形初期(ε=0.002),AZ31镁合金挤压板中就生成了大量呈条带状分布的孪晶,条带走向与拉伸方向垂直,在整个拉伸过程中孪晶数最持续增加.EBSD微观取向分析结果显示,最初生成的大量孪晶都是c轴拉伸孪晶.孪晶取向在{0002}极图中呈双峰形态分布,峰点偏转方向与宏观拉伸方向垂直,偏转角度为±20°-30°,{OOO2}宏观织构强度随变形量的增加呈现波动上升趋势,最终形成双峰形态,偏转方向及角度与EBSD观察到的拉伸孪晶双峰织构一致,因此,孪晶可能是宏观织构形成{0002}双峰形态的重要诱因.由于{11-20} <10-10>取向晶粒中生成大量拉伸孪晶以及孪晶界对滑移的阻碍,拉伸样品表现出低屈服强度和高n值,分别为50 MPa和0.56.
参考文献
| [1] | 丁茹,王伯健,任晨辉,刘长瑞.异步轧制AZ31镁合金板材的晶粒细化及性能[J].稀有金属,2010(01):34-37. |
| [2] | 张康,张奎,李兴刚,李永军,马鸣龙,徐玉磊.均匀化热处理对AZ151镁合金显微组织的影响[J].稀有金属,2009(03):328-332. |
| [3] | Staroselsky A.;Anand L. .A constitutive model for hcp materials deforming by slip and twinning: application to magnesium alloy AZ31B[J].International Journal of Plasticity,2003(10):1843-1864. |
| [4] | 王娜,雷丽萍,方刚,曾攀.镁合金变形的晶体塑性有限元分析[J].稀有金属,2008(06):766-773. |
| [5] | 赵欣,张奎,李兴刚,李永军,何庆彪,孙建锋.Mg-Y-Nd-Gd-Zr稀土镁合金热变形行为[J].稀有金属,2008(03):263-268. |
| [6] | Bohlen J;Nurnberg MR;Senn JW;Letzig D;Agnew SR .The texture and anisotropy of magnesium-zinc-rare earth alloy sheets[J].Acta materialia,2007(6):2101-2112. |
| [7] | Agnew S R;Yoo M H;Tome C N .Application of texturo simu-lation to understanding mechanical behavior of Mg and solid solu-tion alloys wntaining Li or Y[J].Acta Materialia,2001,49:4277. |
| [8] | Kelley E W;Hosford W F .Plane-strain compression of magne-sium alloy crystal[J].Metal Traps,1968,242:5. |
| [9] | Styczynski A;Hartig Ch;Bohlen J;Letzig D .Cold rolling tex-tures in AZ31 wrought magnesium alloy[J].Scripta Materialia,2004,50:943. |
| [10] | 孟利 .镁合金热、温形变行为的EBSD微织构研究[D].北京科技大学,2008. |
| [11] | Barnett MR .Twinning and the ductility of magnesium alloys Part I: "Tension" twins[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2007(1-2):1-7. |
| [12] | Rouwules C;Pietrzyk M;Hod.eon P D .Analysis of work hsrd-ening and recrystallization during the hot working of steel using a statistically based internal variable model[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2003,339:1. |
| [13] | Yang P;Yu Y;Chen L;Mao W .Experimental determination and theoretical prediction of twin orientations in magnesium alloy A731[J].Scripta Materialia,2004,50:1163. |
| [14] | Barnett M R;Keshavarz Z;Ma X .A semianalytical sacks mod-el for the flow stress of a magnesium alloy[J].Materials Transactions A,2006,37(07):2283. |
| [15] | J. Jain;W.J. Poole;C.W. Sinclair .Reducing the tension-compression yield asymmetry in a Mg-8Al-0.5Zn alloy via precipitation[J].Scripta materialia,2010(5):301-304. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%