Untersuchungen zur Festigkeit von Schrauben aus ultrafeinkörnigem und konventionellem Aluminiumwerkstoff EN AW‐7075

Abstract

Results of investigation into strength and fracture behaviour with high level mean load of rolled 7075-aluminiumbolts M6 are given. Bolts made of coarse grain as well as ultra fine grain structure produced by Equal Channel Angular Extrusion (ECAE) were tested. The ultimate tensile strength for both grain sizes was of a similar level. As a result of the first fatigue tests it seems that the fatigue strength of the ultra fine grain material is lower that the fatigue strength of the coarse grain material. An endurance limit of 23 MPa was found for the bolts made of coarse grain material using a modified staircase method. Furthermore, fracture behaviour of aluminium bolts is discussed.