关键词: 飞机铝合金零件, 涂层老化, 点腐蚀, 海洋环境, 微裂纹

Abstract: In order to study the corrosion of aluminum alloy parts used on airplanes serving in the tropical coastal environment of Fiji, the effect of the aging and failure of the coatings on the corrosion of aluminum alloy parts and the main causes for the corrosion of these parts was researched. The aging and failure characteristic of the coatings was discussed in the condition of a neutral salt spray and ultraviolet ray in the laboratory, by examining the macro and micro images, and analyzing the composition of corrosion products. The results show that the aging and failure of the coatings emerges first on the surface of the aluminum alloy parts on airplanes in the coastal and laboratory environment. Subsequently pitting corrosion occurs on the anodic oxidation film and aluminum alloy, which continues until intergranular corrosion and exfoliation corrosion take place. The origin of the aging and failure of coatings on aluminum alloy parts is such deficiencies as pinholes and cracks produced by the combined effect of temperature, moisture, Cl^-, and sunlight in the tropical environment.

Key words: aluminum alloy parts on airplanes, aging of coating, pitting corrosion, coastal environment, micro-cracks