LY12铝合金在周浸试验中的腐蚀行为

CORROSION BEHAVIOR OF LY12 ALUMINUM ALLOY WITH CYCLIC IMMERSION CORROSION TEST

用电化学阻抗谱(EIS)、扫描电子显微镜(SEM)和X射线能谱分析(EDAX)等检测技术,研究了LY12铝合金在周浸实验中的腐蚀行为及其机理。结果表明,LY12铝合金的腐蚀动力学符合幂函数规律.腐蚀历程为点蚀-晶间腐蚀-剥蚀(鼓泡)。EIS谱由高-中频容抗弧和低频收缩的感抗弧组成.

The corrosion behavior of LY12 aluminum alloy was studied with cyclic immersion test, associated with electrochemical impedance spectroscopy （EIS）, scanning electron microscope （SEM） equipped with energy dispersive analysis system of X-ray （EDAX） examination. The results showed that the corrosion of LY12 aluminum alloy started from pitting, and then to intergranular corrosion and exfoliation. EIS is comprised by three capacitive curves at high-mediate frequency and a shrinking inductive curve at low frequency. Some information about the corrosion mechanism, such as corrosion development rate, corrosion morphology, the variation of the interface and the protection of the corrosion product, can be obtained through the simulated EIS data combined with the analysis of the corrosion kinetics and the corrosion product.