Microtexture Development and Flow Stress Saturation during Triaxial Forging of an Al-3Mg-Sc(Zr) Alloy

Abstract

An Al-3%Mg-0.25%Sc-0.12%Zr alloy was deformed by triaxial forging at 20-400°C up to strains of about 3. A study of its textural evolution reveals the tendency towards three symmetrical variants of a <110><1 10 ><001> component. This experimental observation is supported by a 3D spatially resolved crystal plasticity analysis. Samples strained at room temperature undergo grain fragmentation in the form of fine substructures and relatively weak textures. Conversely, at 300°C and above, more homogeneous intergranular deformation and rotations give rise to stronger textures. This eventually encourages grain coalescence and thus the development of interpenetrating “orientation chains”, creating a new type of microstructure. The influence of this texture development on the specific work hardening behaviour is discussed.