LY12CZ 合金相电化学腐蚀行为的研究

 分别研究了LY12CZ合金中的纯铝（Al）、晶间化合物θ（CuAl2）、S（Al2CuMg）和MnAl6在含Cl-离子的中性溶液中的电化学腐蚀行为。结果表明，各合金相作为独立相在含Cl-离子的中性介质中均有点蚀敏感性，其中S相耐蚀性最差，L1相耐蚀性最好。各相点蚀主要是由于Al或Mg的阳极溶解所致，腐蚀产物主要是铝的不溶性氢氧化物、可溶性氯化物及镁的可溶性盐类。

THE ELECTROCHEMICAL CORROSION BEHAVIOUR OF THE INTERMETALLIC COMPOUNDS OF LY12CZ ALUMINIUM ALLOY

The electrochemical corrosion behaviour of the LY12CZ aluminium alloy, the L1(pure Al) and the intermetallic compounds of θ phase (CuAl 2),S phase (Al 2CuMg),and MnAl 6 was studied respectively in the Cl - ion containing neutral solution. These compounds were the main grain boundary precipitates of LY12CZ aluminium alloy. For each compound, the variation of the corrosion potential with time, and the anodic polarization curves were measured. Besides, the corrosion morphology and the corrosion products were studied by SEM and EDAX. The results showed that the pitting corrosion occurred there in all the phase, among others the corrosion resistance of S phase was the poorest and the L1 phase was the best. The pitting resulted mainly from the anodic dissolution of Al and Mg. The corrosion products were mainly insoluble aluminium hydroxides,soluble aluminium chlorides and soluble magnisium salts. The Cu and Mn were cathode of the microelectrochemical cells during the pitting corrosion.