预时效温度及回归加热速率对7055铝合金组织及性能的影响

Effect of pre-ageing temperature and retrogression heating rate on microstructure and properties of 7055 aluminium alloy

利用硬度、电导率与拉伸性能测试,结合差示扫描量热法(DSC)和透射电镜(TEM)研究预时效温度和回归加热速率对7055铝合金力学性能和电导率的影响,并讨论各RRA制度下微观组织的变化。结果表明:由于7055铝合金中厚板在回归加热过程中存在慢速升温过程,近峰时效作为预时效制度更适合7055铝合金中厚板的回归再时效处理。经过(105℃,24 h)→3°/min(190℃,50 min)+(120℃,24 h)的三级时效处理,7055铝合金中厚板强度和电导率优于T6和T73状态的综合性能。

The effect of pre-aging temperature and retrogression heating rate on the mechanical properties and electrical conductivity of the RRA treated 7055 aluminium alloy were investigated by hardness, electrical conductivity, tensile properties test, differential scanning calorimetry （DSC） and transmission electron microscope （TEM）. The microstructures under various RRA treated samples were discussed. The results reveal that, near peak aged state, the pre-aging treatment is more applicable to industrial processing due to the slow retrogression heating rates in 7055 aluminium alloy middle thick plate. After （105℃, 24 h）？3？℃/？m？in→（190℃, 50 min）＋（120℃, 24 h） treating, the 7055 aluminum alloy possess a better combination of both strength and electrical conductivity than those of T6 and T73 state.