Mechanical properties and microstructure evolution of an Al–Cu–Li alloy via cross cryorolling

Abstract

The anisotropy of mechanical properties limits the applications of Al–Cu–Li alloys. In this study, microstructure evolution and mechanical properties of an Al–Cu–Li alloy via room-temperature rolling (RTR), room-temperature cross rolling (RCR), cryorolling (CR) and cross cryorolling (CCR) were investigated. The processing of Al–Cu–Li alloy by CCR gave the highest ultimate tensile strength of 471 MPa and an elongation of 8.4% along rolling direction (RD). The elongation of the CCR alloy along the diagonal direction (DD) was higher than those processed by CR, RCR, and RTR. The in-plane anisotropy (IPA) factor of the ultimate tensile strength (3.26%) of the CCR alloy indicated its relatively low anisotropy of the strength. Kernel average mapping (KAM) showed that the deformation was relatively uniform for the CCR alloy. A prominent local low KAM zone appeared in the alloy processed by RCR and RTR. The alloy in the CCR condition exhibits the highest strain hardening rate, progressively decreasing in a sequence of CR, RCR, and RTR. The refined grains and the texture, including mainly copper texture, little Cube texture, little Goss texture and little S texture, are the main reasons for the excellent mechanical properties and balanced strength-ductility of the CCR alloys.

Keywords

• Al–Cu–Li alloy
• Cross rolling
• Mechanical properties
• Texture evolution