Fatigue behavior of 2618-T851 aluminum alloy under uniaxial and multiaxial loadings

•Fatigue behavior resistance of 2618 aluminum alloy is sensitive to mean tensile stress as well as mean shear stress.•Whatever the loading is, fatigue cracks initiate systematically on Al9FeNi coarse intermetallic particles.•Crossland generalized fatigue criterion is not able to reproduce correctly the experimental results. AA2618 aeronautical aluminum alloy has been largely used in the past, especially in well-known Concorde aircraft, developed during sixties decade. In more recent aircraft, this alloy has been largely replaced by others such as 7075 which present greater fatigue resistance. Forgotten for a time, AA2618 comes back in new aircrafts for structural parts submitted to fatigue loading at high temperature because of only a slight decrease of fatigue resistance of this alloy compared to room temperature fatigue resistance. In this paper, a complete fatigue characterization of 2618-T851 aluminum alloy is presented: fatigue tests under uniaxial tensile or torsion cyclic loadings, with mean tensile or shear stress have been realized; fatigue tests under combined tensile-torsion, in or out-of-phase have also been conducted as well as some combined tensile-torsion-internal pressure fatigue tests. All these tests covered 104–107 cycles range. At last, Crossland multiaxial fatigue criterion has been used and extended to median fatigue life domain to analyze these results.