Fe和Si含量对2519铝合金组织与力学性能的影响

Effects of Fe and Si on microstructures and mechanical properties of 2519 aluminum alloy

通过显微硬度测试、力学性能测试、扫描电镜和透射电镜分析等手段研究Fe和Si元素的含量对2519铝合金的组织与力学性能的影响。研究结果表明:随着Fe和Si含量的减少,2519铝合金的时效硬化效果逐渐增强;随着Fe和Si含量的增加以及m(Fe)/m(Si)的降低,2519铝合金的抗拉强度逐渐降低;当w(Fe+Si)>0.14%及m(Fe)/m(Si)<2.7时,2519铝合金的抗拉强度随w(Fe+Si)的增加和m(Fe)/m(Si)的降低显著下降;Fe和Si含量较低的合金中的析出相主要是强化相θ′相;Fe和Si含量较高的2519铝合金中,除析出θ′相外,在晶界析出粗大的AlCuFe相,降低了θ′相的数量,合金的强度降低。

Effects of different contents of Fe and Si on microstructures and properties of 2519 aluminum alloy were investigated through micro hardness tests, mechanical property tests, transmission electron microscope （TEM） and scanning electron microscope（SEM）. The results show that the age-hardening gradually increases with the decrease of content of Fe and Si. The strength of the alloy decreases with the increase of Fe and Si as well as the decrease of the mass ratio of Fe to Si. The tensile strength dramatic decreases when the mass fraction of Fe and Si is over 0.14% and the mass ratio of Fe to Si is lower than 2.7. The main precipitated phase of 2519 aluminum alloy with little Fe and Si is 0＇ phase, which is the most important strengthening phase. However, when the mass ratio of Fe and Si is high, coarse AlCuFe phase precipitates at grain boundary and decreases the number of 0＇ phase, which results in the decrease of the strength of 2519 aluminum alloy.