FATIGUE BEHAVIOR OF NEW ECO7175 EXTRUDED ALUMINUM ALLOY

Chinh VU, Chien WERN, Bong-Hwan KIM, Shae Kwang KIM, Ho-Joon CHOI, Sung YI
2019
Fatigue characteristics of a new extruded aluminium 7175, with an experimental composition where a magnesium-calcium alloy is used during the alloying process instead of the standard pure magnesium, is investigated. This new aluminium 7175, dubbed as aluminium ECO7175v1, results in a cleaner manufacturing process and improves mechanical properties. The fatigue behavior of the new aluminium ECO7175v1 with T74 temper is investigated. Experimental data showed the fatigue life of ECO7175v1-T74
more » ... ECO7175v1-T74 aluminium can exceed 107 cycles with a fatigue strength of approximately 207 MPa, about 36% of its tensile strength. Fractography results show that failure modes are predominately ductile near the surface while brittle towards the center. In addition, at higher stresses, there are typically more crack initiation points at or near the surface of the specimens compared to specimens at lower stresses. Irrespective of the stresses the specimens are subjected to, all crack initiation points are located near or at the surface and no inclusions to act as stress concentrators are seen.
doi:10.13009/eucass2019-145 fatcat:6kgdrjtdnrc4dbfmrliovt43l4