Influence of exposure to aggressive environment on fatigue behavior of a shot peened high strength aluminum alloy

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Vol. 574; pp. 243 - 252
• Main Authors: Sheng-Li, Lv, Cui, You, Gao, Xiaosheng, Srivatsan, T.S.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.07.2013; Elsevier
• Subjects: Aluminum alloy shot peening; Aluminum base alloys; Applied sciences; Corrosion fatigue; Exact sciences and technology; Fatigue; Fatigue (materials); Fatigue failure; Fatigue life; Fatigue loading; Fractures; Hardening. Tempering; Heat treatment; High strength; Life and fracture; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Pre-corrosion; Production techniques; Shot peening; Surface treatment; Aluminum alloy shot peening; Fatigue loading; Pre-corrosion; Life and fracture; Fatigue life; Fracture life; Fatigue; Shot peening; Fatigue fracture; Surface treatment; Corrosion; Tempering; Cyclic load; Corrosion test; Fractography; Crack initiation; Damaging
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2013.02.055

Pre-corrosion tests were performed on the high strength aluminum alloy 7050 in the T7451 temper that was subject to shot peening surface treatment. This was done for different time intervals and compared one-on-one with samples of the alloy that were not subjected to shot peening. The shot peening surface treatment was conducted for shot peening intensities of 0.006A and 0.008A. The pre-corrosion test specimens were subsequently subjected to fatigue loading and the resultant life was determined with the prime objective of establishing the intrinsic influence of damage due to corrosion on response of the alloy when subjected to cyclic loading. Fatigue fracture surfaces of the non-shot peened samples that were exposed to the environment and concomitant corrosion revealed crack initiation to occur at the pits. The overall fatigue life of the pre-corroded test specimens that were subject to shot peening was noticeably higher than the non-shot peened counterpart. An increase in shot peening intensity on the sample surface revealed an observable improvement in the fatigue life of this high strength aluminum alloy.