Research on Corrosion Damage Evolution of Aluminum Alloy for Aviation

Abstract

Based on the real annual average value of atmospheric environmental data in the Wanning area of Hainan Province in China by selecting 7075 ultra-high-strength aluminum alloy specimens for aviation, a new corrosion solution was designed and the traditional alternate immersion corrosion method of using the alternate immersion corrosion test box was improved to simulate the environment of the internal structure of the aircraft. On this basis, two kinds of corrosion damage parameters, the depth of corrosion pits and corrosion rate, were quickly and accurately obtained by the three-dimensional profile of the specimen and binarization images’ method. The optimal linear regression equation combination of pitting depth and corrosion rate was established, and the dynamic evolution equation of the depth of corrosion pits and corrosion rate was obtained. The results showed that: The depth of corrosion pits in the early stage of corrosion (8 h and 24 h) obeyed the Gumbel distribution and Weibull distribution, respectively, and the later stage (48 h, 72 h, 96 h, and 120 h) conformed to the normal distribution; the depth of corrosion pits’ evolution law was in the form of double straight lines and the corrosion rate evolution law was in the power function form (y = a × xb); and the depth of corrosion pits changed rapidly in the early stage and gradually slowed down in the later stage, while the corrosion rate was just the opposite.

KIc Determination of a 7075 T6 Aluminum Alloy by Critical Distances Theory and LEFM

“…Once that weight reduction is one crucial aspect of aircraft design 9 , recent prognosis programs for aging military aircraft have revived research on high strength 7075-T6 series aluminum alloys that have been used as structural materials for airframes 10 . This alloy plays an irreplaceable role in the Aviation Industry field, such as aircraft wing panel, wing beam, wing rib, and fuselage internal support components 11 . Moreover, there is an increasing demand for the use of age hardenable alloy within the Automotive Industry, due to its advantages of high strength-to-weight ratio, good corrosion resistance and formability 12 .…”