Anisotropy of the creep strength of aluminum alloys

Abstract

1. Extruded strips and rolled slabs of alloy D16 in the naturally aged condition exhibit considerable anisotropy of the creep strength at 135°. The creep strength is highest in the longitudinal direction and lowest along the thickness of the strip. 2. Extruded strips of alloy AK4-1 have the lowest anisotropy of the creep strength in tests for more than 1000 h as compared with other semifinished products. 3. Extruded strips of alloy VAD23 have the largest anisotropy of the creep strength at 135°. 4. Artificial aging and an increase of the testing time under load reduce the anisotropy of the creep strength of semifinished products of alloys D16 and AK4-1. 5. The additional aging that occurs in the process of creep tests is anisotropic. 6. The magnitude and character of the change in the anisotropy of the strength and ductility under creep conditions at 135° differ. The anisotropy of the ductility (δ, ψ) exceeds the anisotropy of the creep strength. 7. The presence of a stress concentrator increases the anisotropy of the creep strength at 135°, the anisotropy increasing with testing time.