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采用硬度测试、电导率测试、常温力学性能测试等方法研究了单级时效处理过程中时效温度和时效时间对Al-2.3Cu-1.7Mg-1.2Fe-1.2Ni合金力学性能和电导率的影响规律,并利用金相显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)、选区电子衍射(SAED)等手段对合金淬火态以及几种不同时效处理制度下的显微组织进行了研究。结果表明,合金经固溶淬火处理后仍残留有较多的大尺寸第二相,淬火态组织存在的第二相主要有Al9FeNi,Al7Cu2Fe,Al7Cu4Ni等。单级时效处理过程中,时效处理的温度越高,达到峰时效所需的时间越短,材料的峰时效硬度值越低;电导率随时效时间的延长而不断上升,时效温度越高,电导率的增长速率越快。峰时效条件下合金内主要沉淀强化相包括S’相和S″相,晶界上有明显的链状析出物存在,呈不连续分布;峰时效条件下,合金棒材的极限抗拉强度、屈服强度和延伸率分别为455 MPa,391 MPa和10.6%,电导率可达到21.6 MS.m-1。
The effects of aging temperature and aging time on mechanical properties and electrical conductivity of Al-2.3Cu-1.7Mg-1.2Fe-1.2Ni alloy were studied by means of hardness test, conductivity test and mechanical properties test at room temperature The microstructures of the alloy under quenched state and under several different aging treatments were studied by means of OM, SEM, TEM and SAED. The results show that there are still many large second phases in the alloy after solution quenching, and the second phases in quenched microstructure are mainly Al9FeNi, Al7Cu2Fe, Al7Cu4Ni and so on. During the single-stage aging treatment, the higher the temperature of aging treatment is, the shorter the time required to reach peak aging is, the lower the peak aging hardness of the material is. The conductivity increases with the aging time, and the higher the aging temperature is, the higher the conductance The rate of increase faster. Under the condition of peak aging, the main precipitation strengthening phases in the alloy include S ’phase and S "phase, and obvious chain-like precipitates exist in the grain boundary and are discontinuously distributed. Under the condition of peak aging, the ultimate tensile strength, The yield strength and elongation were 455 MPa, 391 MPa and 10.6% respectively, and the conductivity reached 21.6 MS.m-1.