纳米晶Al-Mg-Si-Cu铝合金的微观结构、力学性能和时效相演变  

Microstructure,mechanical properties and precipitation evolution of nanocrystalline Al-Mg-Si-Cu aluminum alloy

作　　者：刘满平[1,2] 任晓宇 陈昱林 贾志宏 丁立鹏 Hans J ROVEN LIU Man-ping;REN Xiao-yu;CHEN Yu-lin;JIA Zhi-hong;DING Li-peng;Hans J ROVEN(School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,China;The State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082;Key Laboratory for Light-weight Materials,Nanjing Tech University,Nanjing 211816,China;School of Materials Science and Engineering,Norwegian University of Science and Technology(NTNU),Trondheim 7491,Norway)

机构地区：[1]江苏大学材料科学与工程学院,镇江212013 [2]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082 [3]南京工业大学先进轻质高性能材料研究中心,南京211816 [4]School of Materials Science and Engineering,Norwegian University of Science and Technology(NTNU),Trondheim 7491,Norway

出　　处：《中国有色金属学报》2023年第6期1695-1706,共12页The Chinese Journal of Nonferrous Metals

基　　金：国家自然科学基金资助项目(U1710124,51871035,52001159);汽车车身先进设计制造国家重点实验室开放基金资助项目(32115014)。

摘　　要：通过变形前在合金内部引入高密度纳米时效相并随之进行高压扭转变形(HPT),可制备具有纳米晶结构的高强高韧Al-Mg-Si-Cu铝合金。采用X线衍射仪、透射电子显微镜、高分辨透射电子显微镜和原子探针层析技术分析了峰时效(T6态)与不同圈数(T)高压扭转变形相结合工艺制备的纳米晶6061铝合金的微观结构,并通过硬度与拉伸实验对不同状态合金进行了力学性能测试。结果表明:T6态合金经HPT 5T变形后,硬度由107HV提高至176HV,抗拉强度和屈服强度分别由297 MPa和234 MPa(T6)提升至620 MPa和555 MPa(HPT 5T),并具有12%的均匀伸长率;此时,合金中各微观结构参数(晶粒粒径、微观应变与位错密度)接近峰值;继续变形时,各参数无明显变化;合金中时效相随HPT变形发生“时效相→破碎→球化→细化→回溶→过饱和固溶体→再析出时效相”的动态演变过程。Nanocrystalline 6061 aluminum alloy were prepared by combining peak aging(T6)and high pressure torsional deformation(HPT)with different turns(T).X-ray diffraction,transmission electron microscopy,high-resolution transmission electron microscopy and atom probe tomography were used to analyze the microstructure of Al-Mg-Si-Cu alloys in different states,and the mechanical properties were tested by hardness and tensile experiments.The results show that the hardness of the T6 alloy is increased from 107HV to 176HV after being deformed by HPT 5T,meanwhile,the tensile and yield strength are 620 MPa and 555 MPa,respectively while maintaining a significant uniform elongation of 15%.The microstructural parameters(grain size,microstrain,and dislocation density)are close to the peak value,and there is no significant change in the parameters after continuous deformation.The dynamic process of“precipitates→broken precipitates→spheroidized precipitates→refinement→back-solution→supersaturated solid solution→re-precipitate”occurs during the aging phase deformation process.

关 键 词：Al-Mg-Si-Cu铝合金 纳米晶 时效相演变 微观结构 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]