Effects of Prior Corrosion with and Without Stress on the Mechanical Properties of 7475-T761 Aluminum Alloy

Abstract

The effect of prior corrosion on the mechanical properties of 7475-T761 aluminum alloy was investigated by immersion test, stress corrosion test, cathode charge method and electrochemical polarization test. Results show that prior corrosion in the solution with 3 wt% NaCl and 0.5 wt% H 2 O 2 leads to mechanical properties deterioration of 7475-T761 aluminum alloy. Moreover, the elongation decreases significantly. This is mainly attributed to electrochemical corrosion and hydrogen embrittlement, in which corrosion plays a major role. Tensile stress promotes the degradation of the mechanical properties by accelerating the pitting corrosion and hydrogen embrittlement.

Effects of pre‐corrosion on mechanical properties of 7B50‐T7751 aluminum alloy in sodium chloride solution

“…This stress induces a high triaxial stress beneath the pit, thereby retarding pit growth and promoting the initiation of intergranular and transgranular cracks (Figure d). With prolonged exposure, micro‐cracks and dislocations around the cracks beneath the pit promote the accumulation and diffusion of H abs , and therefore the depth of the HE‐affected region increases (Figure e) . After an exposure time of 720 h, the average elongation of the corrosion samples and that of the stress corrosion samples decrease significantly due to embrittlement induced by continual hydrogenation, and the samples exhibit similar residual elongation.…”

“…The service life of aircraft is characterized by prolonged ground parking and short flight times. Statistics indicate that parking at the airport constitutes >95% and 65% of the calendar life of military and civilian aircraft, respectively . During this parking period, the surface protective layer of aluminum alloy structures is usually damaged by a humid environment, especially that containing chloride ions (Cl − ).…”

“…Petroyiannis et al reported that the strength and ductility of 2024 and 6013 aluminum alloys decreased significantly, owing to HE induced by corrosion . According to Ye et al, the mechanical properties of 7475‐T761 aluminum alloy deteriorated significantly, owing to prior corrosion with and without stress . Cui et al found that the pre‐corrosion mode has a significant effect on the fatigue life of 7B04 aluminum alloy .…”

Influence Factors of Aluminum–Slag Interfacial Reaction Under Electric Field

“…As aluminum has become one of the most widely used nonferrous metals [1][2][3][4][5][6], there is an increasing demand for ingots of highly controlled impurity elements [7][8][9]. Electro-slag refining (ESR) is an efficient process for alloy purification and has been extensively applied into steel and titanium refining.…”

Mechanical Properties and Microstructure Evolution of AA1100 Aluminum Sheet Processed by Accumulative Press Bonding Process

“…They play a crucial role in the field of modern engineering due to their superior mechanical and metallurgical properties such as good corrosion resistance, machinability, weldability and relatively low cost [3][4][5]. The investigations reported that alloying and age hardening are the best strategies to improve the strength of the aluminum alloys [4,6].…”