采用硬度测试、电导率测试及透射电镜研究固溶后降温预析出处理对7A55铝合金板材力学和腐蚀性能的影响。研究结果表明:随着预析出处理温度降低,基体析出相粗化且密度变小,导致合金时效后硬度和强度降低;晶界析出的平衡相由连续链状分布逐渐变为不连续分布,连续网状的腐蚀通道转变为断续的腐蚀点,7A55铝合金抗晶间腐蚀和剥落腐蚀性能提高。
The influence of pre-precipitation after solution on mechanical properties and corrosion resistance of aluminium alloy 7A55 was investigated by means of hardness tests, conductivity tests and transmission electron microscopy (TEM). The results show that with the decrease of pre-precipitation temperature, the age-hardening precipitates in the matrix become less dispersed and coarsened, which decreases the hardness and strength. Meanwhile grain boundary precipitates are discontinuously distributed and more-spaced through pre-precipitation, the resistance to intergranular corrosion and exfoliation corrosion of aluminium alloy 7A55 are improved.