摘要
对7075铝合金进行均匀化处理、固溶处理和不同时效时间(0~24 h)的单级时效处理,通过电子背散射衍射(EBSD)分析、显微维氏硬度测试和室温拉伸试验等研究时效时间对7075铝合金显微组织和力学性能的影响。结果表明,时效处理后7075铝合金组织为等轴晶,随着时效时间的延长,晶粒尺寸、小角度晶界比例和硬度、抗拉强度、断后伸长率均呈先增大后减小或维持稳定的趋势。时效时间为8 h时,晶粒尺寸达到最大值25.6μm,之后维持在20.9~22.4μm;小角度晶界比例达到最大值44.92%,时效24 h后降低至25.19%;硬度达到172.6 HV,之后维持在172.6~175.2 HV。时效时间为4 h时,抗拉强度与断后伸长率均达到最大值,分别为552.0 MPa和36.2%,随着时效时间的继续延长而降低。
The 7075 aluminum alloy was subjected to homogenization treatment,solution treatment and single-stage aging treatment with different aging time of 0 to 24 h.The effects of aging time on the microstructure and mechanical properties of 7075 aluminum alloy were studied by electron backscatter diffraction(EBSD)analysis,Vickers hardness test and room temperature tensile test.The results showed that the 7075 aluminum alloy after aging treatment exhibited equiaxed grain structure.With the extension of aging time,the grain size,the proportion of small angle grain boundaries,hardness,tensile strength and elongation after fracture all showed a trend of increasing first and then decreasing or maintaining stability.When the aging time was 8 h,the grain size reached the maximum of 25.6μm,and then maintained at 20.9 to 22.4μm.The proportion of low-angle grain boundaries reached the maximum of 44.52%,and then decreased to 25.19%after aging for 24 h.The hardness reached 172.6 HV,and then maintained at 172.6 to 175.2 HV.When the aging time was 4 h,the tensile strength and elongation after fracture reached the maximum values,which were 552.0 MPa and 36.2%,respectively,and then decreased with the further aging time.
作者
李晶琨
李欣荻
刘永跃
LI Jingkun;LI Xindi;LIU Yongyue(Hebei Key Laboratory of New Functional Materials,School of Material Science and Engineering,Hebei University of Technology,Tianjin 300401,China;Ningbo Heli Technology Shareholding Co.,Ltd.,Ningbo 315700,Zhejiang,China)
出处
《热处理技术与装备》
2024年第3期1-6,共6页
Heat Treatment Technology and Equipment
基金
宁波市重大科技攻关暨“揭榜挂帅”项目(2022Z013)。
