T6态CNTs/Al-Zn-Mg-Cu复合材料的组织及力学性能研究  

Study on microstructure and mechanical properties of T6 treated CNTs/Al-Zn-Mg-Cu composite

作　　者：何苗[1] 曾敏[1] 张莉[1] 徐九南[1] 王细洋 He Miao;Zeng Min;Zhang Li;Xu Jiunan;Wang Xiyang(School of New Energy Vehicles,Nanchang Institute of Science and Technology,Nanchang 330108,China)

机构地区：[1]南昌工学院新能源车辆学院,江西南昌330108

出　　处：《轻金属》2021年第8期44-49,共6页Light Metals

基　　金：2018江西省教育厅科学技术重点项目(GJJ181051);江西省教育厅科技课题(GJJ181054)。

摘　　要：本实验中在超声波振动的辅助作用下,利用熔融铸造法制备了12 vol.%含量CNTs增强Al-Zn-Mg-Cu复合材料。通过光学显微镜、扫描电镜、能谱分析、拉伸及硬度测试研究了T6热处理对12 vol.%CNTs/Al-Zn-Mg-Cu复合材料的微观组织及力学性能的影响。在470℃固溶处理3 h后,沿晶界偏析的Mg(Zn,Cu,Al)2相溶入铝基体形成过饱和固溶体,因为Al 7Cu 2Fe相熔点过高,其形貌没有发生明显变化。在120℃低温时效处理24 h之后MgZn 2相逐渐析出,沉淀相以弥散分布的形式存在于基体中。T6热处理之后的复合材料的显微硬度、抗拉强度和延伸率分别达到了179.23 HV、398.68 MPa与5.90%,与铸态复合材料的力学性能相比分别提高了31.89%、36.29%和210.52%。复合材料经过T6热处理之后断口表面出现了许多大小和深浅不一的韧窝,表现出更好的强度和韧性。In this experiment,with the assistance of ultrasonic vibration,Al-Zn-Mg-Cu composite reinforced with 12 vol.%CNTs was prepared by the method of molten casting.The effect of T6 heat treatment on the microstructure and mechanical properties of 12 vol.%CNTs/Al-Zn-Mg-Cu composites was studied via optical microscope,scanning electron microscope,energy spectrum analysis,tensile and hardness tests.After solution treatment at 470℃for 3 h,the Mg(Zn,Cu,Al)2 phase segregated along the grain boundary dissolved into the matrix to form a supersaturated solid solution.Given that the melting point of the Al 7Cu 2Fe phase was too high,its morphology did not change significantly.After aging treatment at 120℃for 24 h,the MgZn 2 phase gradually precipitated out,and the precipitated phase existed in the matrix in the form of dispersion distribution.The microhardness,tensile strength and elongation of the composite after T6 heat treatment reached 179.23 HV,398.68 MPa and 5.90%,respectively,which were increased by 31.89%,36.29%and 210.52%compared with the mechanical properties of the as-cast composite.After T6 heat treatment of the composite,dimples of many different sizes and depths appeared on the fracture surface,indicating better strength and ductility.

关 键 词：CNTs/Al-Zn-Mg-Cu复合材料 T6热处理 显微组织 力学性能 

分 类 号：TB331[一般工业技术—材料科学与工程]