EVALUATION ON FATIGUE CHARACTERISTICS OF ALUMINUM ALLOYS BY COMPRESSIVE RESIDUAL STRESS

摘要

Anti-fatigue failure technology takes an important the part of current industries. Currently, the shot peening is used for removing the defect from the surface of steel and improving the fatigue strength on surface. Therefore, in this paper, the effect of compressive residual stress of aluminum alloys (Al7075-T6 and Al6061-T6) by shot peening on fatigue characteristics in stress ratio was investigated with considering fracture mechanics. There is difference between shot peening specimen and un-peening specimen. Fatigue crack growth rate of shot peening specimen was lower than that of un-peening specimen. Fatigue life shows more improvement in the shot peening material than in the un-peening material. In this study, shot peening and un-peening materials were used to investigate the fatigue characteristics using fatigue tester (MTS 810, 10 tonf). Also, after examining the fatigue crack growth and fatigue life, in order to investigate the quality of fatigue fracture surface, observation of the aspect of fracture surface was conducted by using SEM.