【摘要】 采用扫描电镜、X光电子能谱、失重法和电化学交流阻抗技术研究了铝合金7A04在0.6mol/L NaCl溶液和0.6mol/L NaCl+0.02mol/LNaHSO3溶液中干湿周浸后的腐蚀行为和规律,并测试了3种材料力学性能的变化。研究结果表明,随试验时间的延长,铝合金腐蚀产物不断增多,腐蚀失重符合指数规律C=Atn,抗拉强度和延伸率呈下降趋势;表面腐蚀产物形貌呈块状,在0.6mol/LNaCl溶液中腐蚀产物主要为氢氧化铝和氯化铝,而在0.6mol/L NaCl+0.02mol/L NaHSO3溶液中腐蚀产物主要为氢氧化铝、氯化铝和硫酸铝。电化学交流阻抗谱显示铝合金7A04在0.6mol/LNaCl+0.02mol/L NaHSO3溶液中的腐蚀速率远大于在0.6mol/L NaCl溶液的腐蚀速率,并探讨了其腐蚀机理。更多还原

【Abstract】 The corrosion behavior of aluminum alloy 7A04 under cyclic wet-dry immersion conditions was investigated in 0.6 mol/L sodium chloride solution and 0.6 mol/L sodium chloride+0.02 mol/L sodium sulfite solution by Scanning electron microscopy (SEM),energy dispersive X-ray detection (EDS),X-ray photoelectron spectroscopy (XPS),mass loss method,mechanical capability test and electrochemical impedance spectroscopy (EIS). The results showed that the mass loss increases with corrosion time prolonging,and according with the rule as C=Atn,strength and elongation percentage are declining. Surface observation revealed that corrosion product is agglomerated and accidented. The corrosion products are Al(OH)3 and aluminum chloride in 0.6 mol/L sodium chloride solution,and Al(OH)3,aluminum sulfate and chloride in 0.6 mol/L sodium chloride and 0.02 mol/L sodium sulfite solution. The EIS results indicated that corrosion rate in 0.6 mol/L sodium chloride and 0.02 mol/L sodium sulfite solution is higher than that in 0.6 mol/L sodium chloride solution. The corrosion reaction mechanism was discussed.更多还原