铝合金在模拟海岛环境中腐蚀产物的红外光谱研究

目的研究弹药金属元件中铝合金材料在高湿、高盐雾环境中的腐蚀规律。方法在模拟海岛环境的高湿、高盐雾条件下研究铝合金的腐蚀过程,利用红外光谱法(IR)对腐蚀产物进行表征,并对其腐蚀机理作出初步探讨。结果铝合金暴露在潮湿的空气中,在其表面易于吸附一层薄的液层,液层中发生电化学反应,在铝合金表面生成一层Al(OH)3,同时Al(OH)3慢慢脱水后就形成了更为稳定的Al2O3。结论当铝合金表面沉积有盐粒时,由于Cl-的强侵蚀性和Na Cl的潮解作用,在铝合金试样表面形成了无数的微电池,最终导致Al2O3保护膜的破裂,腐蚀介质就会与基体接触,使得腐蚀不断地发展延伸,加快了基体的腐蚀。

IR Analysis of Corrosion Products on Aluminum Alloy in Simulate Island Environments

Objective To study the corrosion behavior of aluminum alloy of ammunition metal materials in the environment with high temperature and high salt fog condition. Methods The corrosion process of aluminum alloy was investigated on the simulate island environment with high temperature and high salt fog condition. The corrosion products were characterized by fourier transform infrared spectroscopy (FT-IR), and a preliminary discussion of the corrosion mechanism was made. Results Aluminum alloy exposed to damp air may easily adsorb a thin layer of liquid, and the electrochemical reaction occurs in the liquid layer. Al(OH)3 was generated on the surface of aluminum alloy, then a more stable Al2O3 was formed after slow dehydration of Al(OH)3. Conclusion When the aluminum alloy surface was deposed with salt, numerous microbatteries will form due to the strong erosion of Cl- and the deliquescence of NaCl, which eventually led to the rupture of Al2O3 protective membrane. Moreover, the corrosive medium then will be in contact with the substrate, which may progressively extension of corrosion and accelerate the corrosion of substrate.