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采用浸泡模拟实验方法、电化学极化和电化学阻抗谱测试技术,研究了Cl~-浓度对SiC_P/Al复合材料电化学腐蚀行为的影响。结果表明:SiC_P/Al复合材料在Cl~-介质下钝化现象不明显,腐蚀过程主要为点蚀腐蚀。随Cl~-浓度增加,SiC_P/Al复合材料腐蚀速率增加,点蚀电位降低,且复合材料的腐蚀过程机制表现为由单纯电荷传递过程机制向电荷传递过程与腐蚀产物扩散共同作用的混合机制转变。电化学阻抗谱随Cl~-浓度增加呈现出2种类型:单一容抗弧类型、高频区容抗弧和低频区一条与实轴呈45°直线(经典Warburg阻抗)组合的复合类型。
The effect of Cl ~ - concentration on the electrochemical corrosion behavior of SiC_P / Al composites was studied by immersion simulation experiment, electrochemical polarization and electrochemical impedance spectroscopy. The results show that the passivation of SiC_P / Al composites under Cl ~ - medium is not obvious, and the corrosion process is mainly pitting corrosion. With the increase of Cl ~ -, the corrosion rate of SiC_P / Al composites increases and the pitting potential decreases, and the corrosion mechanism of the composites changes from pure charge transfer mechanism to mixed mechanism of charge transfer process and corrosion product diffusion . Electrochemical impedance spectroscopy showed two types with the increase of Cl ~ - concentration: a single capacitive arc type, a capacitive arc with high frequency region, and a composite type with a 45 ° straight line (classical Warburg impedance) in the low frequency region and a 45 ° straight line.