Abstract In this paper, the precipitation of second phase particles, hardness and stress corrosion behavior of 7N01 alloys during 120 °C aging are systematically investigated by using micro-hardness tester, transmission electron microscope (TEM), selected area election diffraction patterns (SAEDP) and slow strain rate test (SSRT). The experimental results show that when 7N01 aluminum alloy was aged at 120 °C, the GPII zones formed at first, then gradually dissolved, transformed into η′ phase, and eventually evolved into η′ phase. Accordingly, three peak values appear on the hardness curve. The electrochemical measurements and SSRT results show that the high potential differences and the precipitates distributed continuously in the grain boundary can obviously decrease the stress corrosion cracking of the alloy after aging for 94 h. The narrow PFZ and the precipitates distributed discontinuously in the grain boundary effectively increase the resistance of stress corrosion cracking (SCC) of the alloy after aging for 46 h and 122 h.

中文翻译：

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揭示时效时间对7N01铝合金析出过程及应力腐蚀性能的影响

摘要 本文利用显微硬度计、透射电子显微镜（TEM）、选区选举衍射图谱（SAEDP）系统研究了 7N01 合金在 120 °C 时效过程中第二相颗粒的析出、硬度和应力腐蚀行为。和慢应变率试验（SSRT）。实验结果表明，7N01铝合金在120℃时效时，首先形成GPII区，然后逐渐溶解，转变为η'相，最终演化为η'相。因此，硬度曲线上出现三个峰值。电化学测量和SSRT结果表明，高电位差和连续分布在晶界的析出物可以显着降低时效94 h后合金的应力腐蚀开裂。