Enhanced particle redistribution and texture weakening in 2055 Al–Li alloy by corrugated-flat rolling

A 2055 Al-Li alloy sheet with excellent shape, no edge cracks, and superior room-temperature mechanical properties was successfully fabricated using a novel corrugated-flat rolling (CFR) process with a total reduction of 67.5%. The microstructural evolution and tensile properties of the CFR-processed sheet were systematically compared with those of a conventionally flat-rolled (FFR) sheet through Abaqus numerical simulation and experimental characterization. The first pass, involving hot corrugated rolling (30% reduction), generated a highly inhomogeneous periodic strain distribution across the peaks, waists, and troughs. This strain field produced a heterogeneous grain structure while simultaneously fragmenting and uniformly redistributing second-phase particles. A subsequent cold flat-rolling pass (35% reduction) further refined and homogenized the microstructure, promoted facilitated dislocation propagation, while also weakening the rolling texture. These combined effects resulted in enhanced tensile strength and ductility and a ductile fracture mode in the CFR-processed sample. In contrast, FFR produced a relatively uniform strain field, which resulted in a more uniform, finer fibrous grain structure and a stronger rolling texture. This combination led to higher tensile strength but poor ductility, with failure ultimately occurring by brittle fracture. It is concluded that corrugated rolling is an effective strategy for improving the formability of difficult-to-deform high-strength Al-Li alloys.