Fractographic analysis of the overload effect on fatigue crack growth in 2024-T3 and 7075-T6 Al alloys  

作　　者：A.Albedah B.Bachir Bouiadjra S.M.A.K.Mohammed F.Benyahia 

机构地区：[1]Mechanical Engineering Department,College of Engineering,King Saud University,P.O.Box 800,Riyadh 11421,Saudi Arabia [2]LMPM,Department of Mechanical Engineering,University of Sidi Bel Abbes,BP 89,CitéBen M’hidi,Sidi Bel Abbes 22000,Algeria [3]Department of Mechanical and Industrial Engineering,Ryerson University,Toronto,Ontario M5B 2K3,Canada

出　　处：《International Journal of Minerals,Metallurgy and Materials》2020年第1期83-90,共8页矿物冶金与材料学报（英文版）

基　　金：the Deanship of Scientific Research at King Saud University for funding the work through the research group (No. RGP-VPP-035)

摘　　要：The effect of single overload on the fatigue crack growth in 2024-T3 and 7075-T6 Al alloys was analyzed.Fatigue tests under constantamplitude loading with overload peak were carried out on V-notched specimens.Fractographic analysis was used as a principal approach to explain the crack growth retardation due to the overload.Scanning electron microscopy(SEM)analyses were conducted on the fractured surface of failed specimens to study the retardation effect.The obtained results show that the overload application generates a plastic zone in both aluminum alloys.The generated plastic zone is three times larger in the case of 2024-T3 compared to 7075-T6,and thus,a significant crack retardation was induced for 2024-T3.The retardation effect due to the overload for 2024-T3 and 7075-T6 lasted for about 10 mm and 1 mm,respectively,from the point of overload application.The effect of single overload on the fatigue crack growth in 2024-T3 and 7075-T6 Al alloys was analyzed. Fatigue tests under constantamplitude loading with overload peak were carried out on V-notched specimens. Fractographic analysis was used as a principal approach to explain the crack growth retardation due to the overload. Scanning electron microscopy(SEM) analyses were conducted on the fractured surface of failed specimens to study the retardation effect. The obtained results show that the overload application generates a plastic zone in both aluminum alloys. The generated plastic zone is three times larger in the case of 2024-T3 compared to 7075-T6, and thus, a significant crack retardation was induced for 2024-T3. The retardation effect due to the overload for 2024-T3 and 7075-T6 lasted for about 10 mm and 1 mm, respectively, from the point of overload application.

关 键 词：fatigue crack growth OVERLOAD RETARDATION FRACTOGRAPHY crack tip plasticity 

分 类 号：TG146.21[一般工业技术—材料科学与工程] V25[金属学及工艺—金属材料]