封蕾,李建国,毛轶哲.高镁低钪Al-Mg-Sc-Zr合金强韧化机理研究[J].稀有金属材料与工程,2019,48(9):2857~2863.[Feng Lei,Li Jianguo,Mao Yizhe.Strengthening and toughening mechanisam of high Mg low Sc Al-Mg-Sc-Zr alloy[J].Rare Metal Materials and Engineering,2019,48(9):2857~2863.]
高镁低钪Al-Mg-Sc-Zr合金强韧化机理研究
投稿时间:2018-05-14  修订日期:2018-07-03
中文关键词:  Al-Mg-Sc-Zr合金  Al3(Sc,Zr)相  双峰晶粒  亚晶粒  强化机制
基金项目:清华大学自主科研计划及中国国家科技部国际科技合作专项资金(No. 2015DFR50470)资助
中文摘要:
      本文通过常规轧制与退火工艺制备了具有高抗拉强度(~502MPa)和高断后延伸率(~22%)的高镁低钪Al-Mg-Sc-Zr合金,退火工艺为673K/1h。通过X射线衍射仪(XRD)、电子背散射衍射仪(EBSD)和透射电子显微镜(TEM)等手段,研究了合金退火后的组织及其强化机制。结果表明:Al-Mg-Sc-Zr合金在退火后获得了具有尺寸为0.42 μm的小晶粒和尺寸为16.2μm的大晶粒的双峰晶粒组织,固溶镁原子与Al3(Sc,Zr)相的存在与共同作用促进了具有较大晶格畸变、存在大量亚晶及均匀弥散分布析出相的双峰晶粒组织的形成;合金主要强化方式为镁原子的固溶强化、亚晶界阻碍位错引起的亚晶界强化、细晶强化和Al3(Sc,Zr)相的弥散强化,且合金计算与实测屈服强度相吻合;高镁固溶度、Al3(Sc,Zr)相、双峰晶粒及再结晶织构的存在为位错增殖提供了空间,提高了合金加工硬化率,进而提高了合金的延伸率。
Strengthening and toughening mechanisam of high Mg low Sc Al-Mg-Sc-Zr alloy
英文关键词:Al-Mg-Sc-Zr alloy  Bimodal grain structure  Al3(Sc,Zr) precipitate  Sub-grain  Strengthening mechanism
英文摘要:
      In current research, a novel Al-Mg-Sc-Zr alloy was produced through conventional rolling and annealing process and achieved a high thermal stability, a high ultimate strength (UTS) of 501.7 MPa, a high yield strength (YS) of 320.4 MPa and a high elongation to failure of 21.6%. X-ray diffraction(XRD), electron backscattered diffraction (EBSD) and transmission electron microscope (TEM) were utilized to observe the microstructure of samples. As a result, complex effects of solute Mg atoms and precipitate of Al3(Sc,Zr) precipitation promoted formation of microstructure with large lattice misfit, sub-grain and dispersive distributed Al3(Sc,Zr) precipitation. The main mechanisms for observed high strength were found to be due to the solid solution of Mg and precipitate of Al3(Sc,Zr) precipitation, theoretical strength is in agreement with experimental strength. The presence of bimodal grain structure which was first found in conventional rolling structure and Al3(Sc,Zr) precipitation provided space for dislocation accumulation, improved the dislocation storage capacity of the alloy, and then directly increases the elongation of the alloy.
作者单位E-mail
封蕾 清华大学材料学院先进材料教育部国家重点实验室 fenglei20120830@163.com 
李建国 清华大学材料学院先进材料教育部国家重点实验室 jg.li@mail.tsinghua.edu.cn 
毛轶哲 清华大学材料学院先进材料教育部国家重点实验室 maoyizhebit@126.com 
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