航空铝合金点蚀行为微观结构影响因素分析

Microstructure Influencing Factors of Aero Aluminum Alloy Pitting Corrosion Behavior

目的为进一步深入理解铝合金点蚀行为提供理论支持,确定影响铝合金点蚀行为的微观结构因素。方法将铝合金材料于服役环境的点蚀行为视为受众多因素影响的随机过程,基于点蚀电化学腐蚀机理和常体积扩展模型,对影响铝合金点蚀行为因素进行定性和统计分析。结果从铝合金点蚀扩展模型可以看出,影响铝合金点蚀的微观结构因素包括铝合金材料微观组成粒子的尺寸、粒子密度以及微观组成粒子元素的类型。结论铝合金微观粒子尺寸和粒子密度都具有统计特性,可以采用相关分布函数对其分布特性进行统计分析,Cu和Fe粒子对铝合金点蚀行为影响较大。

Objective To offer theory support for deeply understanding the pitting corrosion behavior of aluminum alloy and ascertaining the microstructure factors that affect the pitting corrosion behavior of aluminum alloy. Methods Pitting corrosion of aluminum alloy in the service environment was viewed as a stochastic process which is affected by many factors. Based on the electrochemical corrosion mechanism and constant volume evolution model, qualitative and statistic analyses on microstructure influencing factors of aluminum alloy pitting corrosion were carried out. Results Factors in- fluencing the microstructure of aluminium alloy pitting corrosion included the size of constituent particles, the particle density and the type of the constituent particles. Conclusion Both the size and the density of microscopic particle of aluminum alloy are statistical. Distribution functions related might be adopted to have statistic analysis on its distribution characters. Cu and Fe particles have greater impact on the behavior of aluminum alloy pitting corrosion.