固溶温度对Al-Cu-Mg-Ag合金显微组织与力学性能的影响

通过金相显微镜、透射电镜、扫描电镜和室温拉伸试验研究了固溶温度对Al-Cu-Mg-Ag合金显微组织与力学性能的影响。结果表明: 随着固溶温度提高(500~520 ℃), Al-Cu-Mg-Ag合金在190 ℃/2 h时效过程中析出的Ω相数量密度逐渐增加, 而且Ω相的大小更均匀, 从而导致合金的强度和热稳定性逐渐提高。热暴露(200 ℃/1 000 h)后, Ω相数量密度显著下降, 从而导致Al-Cu-Mg-Ag合金的强度大幅下降。在热暴露过程中, Ω相的直径方向增长速率远远大于厚度方向增长速率。

Effect of Solid-Solution Temperature on Microstructure and Mechanical Properties of Al-Cu-Mg-Ag Alloys

The effect of solid-solution temperature on the microstructure and mechanical properties of Al-Cu-Mg-Ag alloys were studied by metallographic microscope, transmission electron microscope, scanning electron microscope and room temperature tensile test. The results show that as the solution temperature increasing from 500 ℃ to 520 ℃, the quantitative density of Ω phase precipitated during the aging of Al-Cu-Mg-Ag alloy at 190 ℃ for 2 h increases gradually, and the Ω phase becomes more uniform in size. As a result, the strength and thermal stability of the alloy are also improved gradually. After thermal exposure at 200 ℃ for 1 000 h, the quantitative density of Ω phase decreases significantly, leading to a significant decrease in the strength of the Al-Cu-Mg-Ag alloy. It is shown that during the thermal exposure, the growth rate in the diameter direction of Ω phase is much greater than that in the thickness direction.