【摘要】 采用透射电镜观察、硬度和电导率测试等手段研究双级时效对1973高强高韧铝合金组织和性能的影响。结果表明:一级时效温度对合金最终组织和性能的影响不大,二级时效温度和时间对1973铝合金硬度和电导率的影响明显;1973铝合金适宜的双级时效工艺为(120℃,6 h)+(160℃,16 h),在此条件下,合金的硬度和电导率分别为191HV和38.0%(IACS),其显微组织特点为晶内沉淀相呈细小弥散状分布,而合金的晶界沉淀相粗大、呈断续状分布,并且有较明显的无沉淀析出带。合金中主要沉淀相为η’相和η相,此外还有少量的GPⅡ区。更多还原

【Abstract】 The ageing precipitation and hardening behavior of 1973 high strength and high toughness aluminum alloy were studied by means of transmission electron microscopy(TEM),select area electron diffraction(SAED) and hardness measurements at different ageing temperatures.The results show that this alloy has obvious anti-over-aging capability at 120 and 140 ℃.And this alloy can keep the hardness of 195 HV in a long time after peak-ageing.Furthermore,the precipitation sequence of 1973 aluminum alloy can be described as follows: supersaturated solid solution(α)→ GPⅠ/GPⅡ zone→ metastable η’→ stable η→T phase.There are GPⅡ zone and η’ phase with the greatest strengthening effect on the 1973 aluminum alloy during the whole ageing process at 140 ℃.更多还原