CAJ | 학술논문

采用电化学阻抗谱(EIS)和电化学噪声(EN)方法研究回归再时效(RRA)热处理状态下7A60铝合金的点蚀行为，通过扫描电子显微镜(SEM)和能谱仪(EDS)观察和分析合金的组织和第二相颗粒成分。结果表明，7A60铝合金在3.5% NaCl溶液中存在两个腐蚀阶段，并且可以用EIS出现两个电容时间常数的时间和由EN计算出的小波分形维数D的变化来表征。SEM和EDS分析结果表明，在7A60铝合金中，严重的点蚀主要是由阳极相MgZn2引起的，其次是Al2MgCu和 Mg2Si相，Al7Cu2Fe 相对7A60铝合金点蚀行为的影响不大。
채용전화학조항보(EIS)화전화학조성(EN)방법연구회귀재시효(RRA)열처리상태하7A60려합금적점식행위，통과소묘전자현미경(SEM)화능보의(EDS)관찰화분석합금적조직화제이상과립성분。결과표명，7A60려합금재3.5% NaCl용액중존재량개부식계단，병차가이용EIS출현량개전용시간상수적시간화유EN계산출적소파분형유수D적변화래표정。SEM화EDS분석결과표명，재7A60려합금중，엄중적점식주요시유양겁상MgZn2인기적，기차시Al2MgCu화 Mg2Si상，Al7Cu2Fe 상대7A60려합금점식행위적영향불대。
The pitting corrosion behaviors of 7A60 aluminum alloy in the retrogression and re-aging (RRA) temper were investigated by electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques, and the microstructure and the second phase content of the alloy were observed and determined by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The results show that there exist two different corrosion stages for 7A60 alloy in 3.5%NaCl solution, and the corrosion process can be detected by the appearance of EIS spectrum with two capacitive time constants and the wavelet fractal dimension D extracted from EN. SEM and EDS results also demonstrate that severe pitting corrosion in 7A60 alloy is mainly caused by electrochemical active MgZn2 particles, secondly by Al2MgCu and Mg2Si. Al7Cu2Fe particles make little contribution to the pitting corrosion of 7A60 alloy.