热处理温度对2519A铝合金组织性能的影响

Effect of Heat Treatment Temperature on Microstructures and Mechanical Properties of 2519A Aluminum Alloy

采用硬度测试、拉伸测试、透射电镜及扫描电镜观察分析研究了时效温度对2519A铝合金组织性能的影响。结果表明:140℃时效9 h晶内析出少量细小弥散的片状θ′相,晶界处θ析出相细小且呈链状分布,无析出带较窄,合金的强度较低;165℃时效9h晶内普遍析出细小而弥散的强化相θ′相,晶界析出相不连续分布,无析出带较窄,合金力学性能明显提高。190℃时效9 h晶内析出相θ′相数目减少,晶界析出相粗大且沿晶界连续分布,析出相两侧无析出带较宽,合金强度较低。

The influence of ageing temperature on the microstructures and mechanical properties of 2519A aluminum alloy was investigated by hardness test,tensile test,transmission electron microscope（TEM） and scanning electron microscope（SEM）.Results show that,after being aged at 140 ℃ for 9 h,there was a few precipitation of finely dispersed θ′ phase in a form of flake within grains,while grain boundary precipitation of θ′ phase was fine and in a chain-like distribution,with a narrow precipitation-free zone（PEZ） along grain boundaries,resulting in strength of aluminum alloy being lower.After being aged at 165 ℃ for 9 h,finely dispersed θ′ phase precipitated within grains was generally strengthened,while grain boundary precipitation of θ′ phase was discontinuously distributed,with a narrow PEZ along grain boundaries,resulting in the strength of alloy obviously improved.After being aged at 190 ℃ for 9 h,less θ′ phase was precipitated within grains,while grain boundary precipitation was coarse and distributed continuously along grain boundaries,with a wider PEZ on the both sides of precipitated phase,resulting in the strength of alloy being lower.