Dependence of Fracture Toughness on Rolling Direction in Aluminium 7075 Alloys

Being a light metallic engineering material with low density, high specific stiffness and strength, aluminium alloys are promising materials in the fields of aerospace, military and automotive industries. Consumption of aluminium alloys in the forms of sheets and plates has generally increased in global markets over the past 45 years. Rolling directions affect the anisotropy and mechanical properties of the aluminium alloys. In this work, the plane strain fracture toughness K-IC values of 7075 aluminium alloy were measured in plates of three directions and six orientations (L-T, T-L, T-S, S-T, L-S, S-L), using the standard (ASTM E399) compact tension specimens. The results indicate that dependence of fracture toughness of 7075-T651 aluminium alloy on rolling direction is obvious and that K-IC values of T-S and L-T orientations are the highest.