硅酸钠对铝合金的缓蚀作用及对腐蚀疲劳寿命的影响

THE INHIBITION EFFECT AND INFLUENCE OF SODIUM SILICATE ON THE CORROSION FATIGUE LIFE OF ALUMINUM ALLOY

采用电化学极化曲线方法和扫描电子显微镜观察研究了硅酸钠对 L Y12硬铝合金在 3.5 %氯化钠溶液中的缓蚀作用。通过腐蚀疲劳实验研究了硅酸钠对硬铝合金在氯化钠溶液中的腐蚀疲劳 (CF)寿命及腐蚀疲劳裂纹扩展 (CFCP)的影响。实验结果表明 ,硅酸钠的浓度对铝合金的缓蚀作用有很大的影响 ,硅酸钠的加入可提高铝合金在氯化钠溶液中抗点蚀的能力及腐蚀疲劳寿命 ,这种作用主要是通过抑制铝合金的点蚀、减少裂纹源来实现的 。

The inhibitive mechanism of sodium silicate on LY12 aluminum alloy in 3 5%NaCl solutioin was studied by potentiodynamic method and SEM The corrosion fatigue (CF) life and corrosion fatigue crack propagation (CFCP) of aluminum alloy in 3 5%NaCl solution was investigated by corrosion fatigue test The experimental results showed that the concentration of sodium silicate had considerably influence on the inhibitive efficiency Sodium silicate could increase the pitting corrosion resistance of aluminum alloy in 3 5%NaCl solution Sodium silicate could increase the corrosion fatigue life for aluminum alloy in NaCl solution, which was owing to the inhibition of pitting corrosion of aluminum alloy and decrease in the formation of crack sources, but sodium silicate couldnt inhibit the CFCP obviously