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用金属间化合物θ（ＣｕＡｌ２）、Ｓ（Ａｌ２ＣｕＭｇ）、ＭｎＡｌ６与纯Ａｌ（Ｌ１）组成多电极体系，以模拟ＬＹ１２ｃｚ合金的晶界区．通过电化学测试、ＳＥＭ和能谱分析等方法研究了该合金晶间腐蚀机理．证实其晶间腐蚀是由沿晶界偏析的强化相与贫Ｃｕ区所组成的多电极体系引起的．在含Ｃｌ－离子的中性溶液中，Ｓ相是导致晶间腐蚀的主要阳极相．Ｓ相首先发生阳极溶解，随后，贫铜区、ＭｎＡｌ６相逐步随Ｓ相一起溶解．以这种方式沿晶界形成了阳极溶解通道，导致晶间腐蚀．
The intermetallic compounds θ (CuAl2), S (Al2CuMg), MnAl6 and pure Al (L1) make up a multi-electrode system to simulate the grain boundary region of LY12cz alloy. The mechanism of intergranular corrosion was studied by electrochemical test, SEM and energy spectrum analysis. It is confirmed that the intergranular corrosion is caused by the multi-electrode system composed of the strengthening phase segregated along the grain boundary and the Cu-poor region. In neutral solutions containing Cl- ions, S phase is the main anode phase leading to intergranular corrosion. S-phase anodic dissolution occurs first, then, the copper-depleted region, MnAl6 phase gradually with the S-phase dissolved. Anodic dissolution channels are formed along the grain boundaries in this manner, resulting in intergranular corrosion.