Effect of notch on fatigue behavior of 7175 aluminum alloyTuesday (26.05.2020) 18:06 - 18:07
High strength age hardenable aluminum 7XXX series alloys based on the Al–Zn–Mg–Cu system are widely used in the aircraft and automotive industries for structural components because of its exceptionally high strength to weight ratio. Fatigue life of a component depends strongly on its surface condition. Fatigue cracks are generally considered to nucleate at the surface and therefore surface topography plays an important role in determining the fatigue life. It was established that surface roughness is supposed to introduce stress concentrators that encourage the crack nucleation and accelerates the early fatigue crack growth, hence reducing fatigue life compared to perfectly smooth specimens. The present research reports comparative analysis of notch effects on fatigue behavior of aluminum alloy 7175-T7451. The axial fatigue testing was performed at ambient conditions on smooth specimens and with notch on the surface in form of etch pits. Experimental results revealed reduction in fatigue life of specimen with notch due to decrease the nucleation time of crack initiation. Scanning electron microscopy technique was used to observe fracture and estimated step of fatigue crack grow.