热处理对2024合金组织和力学性能的影响

Effect of Heat Treatment on Microstructure and Mechanical Properties of 2024 Alloy

利用光学显微镜、扫描电子显微镜、透射电镜、X射线物相分析仪和电子拉力试验机研究热处理对2024合金组织和力学性能的影响。结果表明:铸态合金主要由α-Al、Al_(2)CuMg、Al_(7)Cu_(2)Fe、Al_(7)Cu_(4)Ni、Al_(9)FeNi相组成;经固溶处理后,第二相仅剩下含Fe的杂质相,Al_(2)CuMg和Al_(7)Cu_(4)Ni相几乎完全固溶进铝基体中;时效处理后,组织中有新相Al_(2)Cu析出,呈颗粒状,亚晶界上析出物长大、球化和不连续分布。铸态、固溶态和时效态的合金抗拉强度分别为489 MPa、501 MPa和551 MPa,合金的固溶强化和析出强化效果明显。

The effects of heat treatment on the microstructure and mechanical properties of 2024 alloy were studied using optical microscope,scanning electron microscope,transmission electron microscope,x-ray phase analyzer,and electronic tensile tester.The results show that the as-cast alloy is mainly composed ofα-Al,Al_(2)CuMg,Al_(7)Cu_(2)Fe,Al_(7)Cu_(4)Ni,Al_(9)FeNi phases;after solid solution,only Fe-containing impurity phases remain,and the Al_(2)CuMg and Al_(7)Cu_(4)Ni phases are almost completely soliddissolved into the aluminum matrix;aging Afterwards,a new phase Al_(2)Cu precipitated out and was granular.The precipitates on the subgrain boundaries grow,spheroidize and discontinuously.The tensile strengths of the alloys in the as-cast,solid-solution,and aging states were 489 MPa,501 MPa,and 551 MPa,respectively.The solid-solution strengthening and precipitation strengthening effects of the alloy were obvious.