通过对热挤压态AZ31镁合金进行组织形貌观察、内摩擦应力测定及蠕变性能测试,研究了热挤压AZ31合金的组织结构和蠕变行为.结果表明：热挤压AZ31镁合金的组织具有带状结构特征,并沿轧制方向分布,且有β-Mg17Al12相在合金中弥散析出.蠕变期间,位错运动的内摩擦力有较强的温度敏感性,随温度增加,内应力值明显降低,致使合金具有较高的蠕变速率.合金在蠕变期间,大量位错的形成与运动是蠕变初期的变形机制;蠕变稳态阶段,高密度位错逐渐束集形成位错胞,进一步发生蠕变期间的动态再结晶.随裂纹在晶界处萌生使蠕变进入第三阶段,而裂纹沿晶界韧性撕裂扩展是合金的蠕变断裂机制.
By means of microstructure observation,internal frictional stress and creep properties measurement,an investigation has been made into the microstructure and creep properties of hot extraction AZ31 alloy.Results show that the microstructure of hot extruded AZ31 alloy possesses strip-like feature which distribute along the extruded direction,and the β-Mg17Al12 particles are dispersedly precipitated in the alloy.During creep,the internal frictional stress values of dislocation movement possess an obvious sensitivity on the applied temperature,and the value of internal frictional stress decrease as the temperature increases,which result in the alloy possessing larger strain rate during creep at high temperature.Significant amount of dislocations activated in the alloy is thought to be the main deformed mechanism in the initial stage of creep.During steady state creep,the denser dislocations are concentrated to form the cells structure,and gradually transformed into the fine subgrain structure due to the occurrence of the dynamic recrystallization.Once the micro-cracks initiate along the grain boundary,the creep of the alloy turns into the tertiary stage.As creep goes on,the cracks are viscously propagated along the boundary,which is thought to be the fracture mechanism of the alloy during creep.
参考文献
| [1] | Zeng X.Q.;Wang Q.D. .STUDY ON IGNITION PROOF MAGNESIUM ALLOY WITH BERYLLIUM AND RARE EARTH ADDITIONS[J].Scripta materialia,2000(5):403-409. |
| [2] | 张丁非,戴庆伟,胡耀波,兰伟,方霖.镁合金板材轧制成型的研究进展[J].材料工程,2009(10):85-90. |
| [3] | 闫蕴琪,张廷杰,邓炬,周廉.耐热镁合金的研究现状与发展方向[J].稀有金属材料与工程,2004(06):561-565. |
| [4] | 田素贵,杨景红,于兴福,孙根荣,金敬铉,徐永波,胡壮麒.AZ31镁合金蠕变初期的变形特征[J].金属学报,2005(04):375-379. |
| [5] | 王丽娜,杨平,夏伟军,陈振华,陈鼎,李萧,孟利.特殊成形工艺下AZ31镁合金的织构及变形机制[J].金属学报,2009(01):58-62. |
| [6] | Watanabe H.;Mukai T.;Kohzu M.;Tanabe S.;Higashi K.;Tsutsui H. .Deformation mechanism in a coarse-grained Mg-Al-Zn alloy at elevated temperatures[J].International Journal of Plasticity,2001(3):387-397. |
| [7] | S. Spigarelli;M. El Mehtedi;M. Cabibbo;E. Evangelista;J. Kaneko;A. Jager;V. Gartnerova .Analysis of high-temperature deformation and microstructure of an AZ31 magnesium alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2007(1-2):197-201. |
| [8] | 张诗昌,宗钦,胡衍生,程晓茹.高温低应力下AZ31镁合金的蠕变性能及蠕变机理[J].机械工程学报,2009(03):291-295. |
| [9] | 杨景红,田素贵,于兴福,张禄廷.Sb对AZ31合金组织和力学性能的影响[J].材料与冶金学报,2004(04):289-293. |
| [10] | 王春建,金青林,周荣,蒋业华.Al、Zn元素对镁合金的晶粒细化机理分析[J].稀有金属材料与工程,2010(z1):208-211. |
| [11] | 梁书锦,王欣,刘祖岩,王尔德.AZ31镁合金不同温度挤压后组织性能研究[J].稀有金属材料与工程,2009(07):1276-1279. |
| [12] | 程晓农,汝金明,莫纪平,许晓静.固溶-大应变-后续热处理态AZ31镁合金的组织和性能[J].稀有金属材料与工程,2009(11):1950-1954. |
| [13] | 汪凌云,黄光杰,陈林,黄光胜,李伟,潘复生.镁合金板材轧制工艺及组织性能分析[J].稀有金属材料与工程,2007(05):910-914. |
| [14] | 杨续跃,张雷.镁合金温变形过程中的孪生及孪晶交叉[J].金属学报,2009(11):1303-1308. |
| [15] | 赵虎,李培杰,何良菊.AZ31镁合金铸轧和常规轧制板的变形组织及形变特征[J].中国有色金属学报,2009(11):1887-1893. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%