Effects of pre-compression on formation of dynamic precipitates and creep anisotropy of hot-extruded AZ91−2Y magnesium alloy  

预压缩对热挤压AZ91−2Y镁合金动态析出相形成及蠕变各向异性的影响

作　　者：Wei LI Huang HUANG Wei-ying HUANG Jian CHEN Sheng-de ZHANG Zhen-yu XIAO Wei QIU 李微;黄煌;黄伟颖;陈荐;张圣德;肖振宇;邱玮(长沙理工大学能源与动力工程学院高效清洁能源利用重点实验室,长沙410114;Japan Electric Power Central Research Institute,Tokyo 240-0196,Japan;湖南大学汽车车身先进设计制造国家重点实验室,长沙410082)

机构地区：[1]Key Laboratory of Efficient&Clean Energy Utilization,School of Energy and Power Engineering,Changsha University of Science&Technology,Changsha 410114,China [2]Japan Electric Power Central Research Institute,Tokyo 240-0196,Japan [3]State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第11期3550-3562,共13页中国有色金属学报（英文版）

基　　金：the National Natural Science Foundation of China(Nos.52075048,52171099 and 52105140);the Natural Science Foundation of Hunan Province,China(No.2021JJ40583);the Science and Technology Innovation Project of Hunan Province,China(No.2018RS3073);the Scientific Research Innovation Project for Graduate Student of Changsha University of Science&Technology,China(No.CX2021SS55);the Double First-class Scientific Research International Cooperation Project of Changsha University of Science and Technology,China(No.2019IC15).

摘　　要：The creep anisotropy behavior under different stresses at 180℃ of hot-extruded AZ91−2Y magnesium alloy with pre-compression(PC)and without pre-compression(NPC)was studied.Microstructure,texture and mechanical properties of the alloy were examined by scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),transmission electron microscopy(TEM)and tensile creep tests.The results revealed that the creep resistance was proportional to the volume fraction of spherical Mg_(17)Al_(12) precipitates.The dynamic precipitation of large volume fraction of lamellar Mg_(17)Al_(12) in NPC samples leads to the basaláañslip as the dominant creep mechanism,and the NPC samples have obvious anisotropy.In the PC samples,dynamic precipitation of large volume fraction of spherical Mg_(17)Al_(12) has inhibitory effect on the basaláañslip.The pyramidalác+añslip and twinning improve the creep anisotropy resistance significantly.研究经预压缩(PC)和未经预压缩(NPC)的热挤压AZ91−2Y镁合金在180℃不同应力下的蠕变各向异性行为。采用扫描电子显微镜(SEM)、电子背散射衍射(EBSD)、透射电子显微镜(TEM)和拉伸蠕变试验对合金的显微组织、织构和力学性能进行分析。结果表明,抗蠕变性能与球形Mg_(17)Al_(12)析出相的体积分数成正比。NPC试样中动态析出高体积分数层片状Mg_(17)Al_(12),使其以基面áañ滑移为主导蠕变机制,且NPC试样具有明显的各向异性。PC试样动态析出高体积分数的球形Mg_(17)Al_(12),对基面áañ滑移有抑制作用。锥面ác+añ滑移和孪晶显著提高蠕变各向异性抗力。

关 键 词：magnesium alloy creep anisotropy pre-compression twin DISLOCATION 

分 类 号：TG146.22[一般工业技术—材料科学与工程]