Microarc Oxidation Coating Combined with Surface Pore-Sealing Treatment Enhances Corrosion Fatigue Performance of 7075-T7351 Al Alloy in Different Media

Abstract

Rotating bending fatigue tests have been performed to evaluate the corrosion fatigue performance and its influence factors of 7075-T7351 Al alloy in different media, namely air and a 5.0 wt % NaCl aqueous solution. All samples were coated by microarc oxidation (MAO) coating technology; some samples were followed by an epoxy resin pore-sealing treatment. Microscopic analyses of the surfaces and fracture cross-sections of samples were carried out. The results reveal that the sample with a MAO coating of 10 μm thickness and pore-sealing treatment by epoxy resin possesses optimal corrosion fatigue performance in the different media. The MAO coating with a pore-sealing treatment significantly improves the corrosion fatigue limit of 7075-T7351 Al alloy.

A study on corrosion‐fatigue behavior of AA7075‐T651 subjected to different surface modification treatments

“…The fatigue strength and crack propagation of several types of aluminum alloy are well documented in literature . However, the synergistic effects, between cyclic alternating mechanical loads and chemical degradation, remain still elusive.…”

“…During the last decade, it has been shown that by using appropriate sealing processes and better quality of coatings surfaces, these hard oxides do not deteriorate the fatigue durability of aluminum Nomenclature: AA, Aluminum Alloy; EDM, Electrical Discharge Machining; FEM, Finite Element Method; MAO, Microarc Oxidation; OCP, Open Circuit Potential; PEO, Plasma Electrolytic Oxidation; SCE, Saturated Calomel Electrode alloys. 8,9 In same cases, they can even provide improvement of the fatigue strength due to the delay of fatigue crack initiation. 8,9 Yang et al 9 conducted fatigue tests in air and 5% NaCl aqueous solution for a coated AA7075-T7351 and studied the effect of the microarc oxidation (MAO) coating and the sealing process in the corrosion-fatigue life.…”

“…14,15 The fatigue strength and crack propagation of several types of aluminum alloy are well documented in literature. 4,[6][7][8][9][10][11][12][13][14][15] However, the synergistic effects, between cyclic alternating mechanical loads and chemical degradation, remain still elusive. High strength Al-alloys find many uses in aerospace and automotive applications for fatigueoriented applications such as components, subjected to severe safety requirements.…”

Influence of Scandium Addition on Stress Corrosion Cracking Susceptibility of Al-Zn-Mg Alloy in Different Corrosive Environments

“…The age-hardenable 7xxx series Al alloys can be divided into medium strength Al-Zn-Mg system and high strength Al-Zn-Mg-Cu system [1][2][3][4][5][6]. Nowadays, 7xxx series alloys are being used in the aerospace and high-speed train system for structural components due to their high strength/weight ratio [7][8][9][10][11][12].…”

Surface modification and fatigue properties of electrical discharge machined aluminum alloy 6061 using plasma etching

“…There are many kinds of surface treatment methods, and different surface treatments can enhance the different performances for various needs. The commonly used treatments include electroless plating, 1,2 electroplating, 3 plasma etching, [4][5][6] ceramic thin film cladding, 7 physical vapor deposition (PVD), 8,9 chemical vapor deposition (CVD), [10][11][12] micro arc oxidation (MAO), [13][14][15][16] plasma electrolytic oxidation (PEO) coating, 17 and so on.…”