The effects of combination of severe plastic deformation and Shot Peening surface treatment on fatigue behavior of 6082 aluminum alloy

In this paper, the effects of Equal Channel Angular Pressing process (ECAP) followed by Shot Peening process (SP) on the fatigue properties of 6082 aluminum alloy are investigated. Several samples of the alloy are ECAPed and SPed and then their mechanical behavior are characterized using tensile, micro-hardness, and fatigue tests. The results indicate that shot peening and then polishing the specimen after one-pass ECAP is an effective method to improve the fatigue life of the alloy. Moreover, by increasing the number of ECAP passes before shot peening, a local work softening occurs at the subsurface layer, leading to a significant decrease in the fatigue life of the alloy. The results of the fractography studies show that the nucleation of fatigue crack moves from the surface of the specimen to the subsurface in the specimens ECAPed more than one pass and then SPed.