Aging time induced phase evolution and defect engineering in a bionic laminar graphene/CuAlMn composites for properties tailoring

This study systematically investigates the influence of aging time on the phase composition, micro-defect evolution, and resultant properties of Cu-11.9Al-2.5Mn (wt%) composites enhanced with copper-coated graphene films (GFs(Cu)). Our results demonstrate that aging at 300 °C effectively enhances the mechanical properties and improves the synergy between strength and damping capacity. The optimal aging duration was identified as 120 min. Under this condition, the microhardness of the composite increased significantly. Correspondingly, due to microstructural optimization, the ultimate tensile strength increased from 415 MPa in the as-quenched state to 521 MPa, representing a 25.5% improvement. Although aging treatment led to a reduction in damping performance compared to the as-quenched state, extending the aging time (notably to 120 min) prompted a recovery and enhancement in damping capacity relative to shorter aging durations (e.g., 30 min). This paper provides an in-depth analysis of the property evolution and underlying strengthening mechanisms, focusing on martensitic defect evolution, interface/twin structure modifications, and dislocation behavior during aging. ... mehrThese findings provide new insights into achieving coupled mechanical-damping properties in balanced biomimetic layered CuAlMn-based composites.