Effect of ball milling time on the mechanical and damping properties of CoCrFeMnNi high entropy alloy reinforced Cu/MnCu laminated composites

CoCrFeMnNi high-entropy alloy (HEA) reinforced Cu/MnCu laminate composites with varied particle morphologies were prepared via mechanical ball milling and vacuum hot-press sintering. Results show that extended ball milling reduces micron-sized HEA particle size, transforming their morphology from spherical to flaky. This enhances geometric compatibility with the matrix and strengthens interfacial bonding, facilitating more efficient load transfer. Concurrently, ball milling exposes highly reactive surface atoms, promoting nano-sized HEA particle formation. These nanoparticles effectively impede dislocation motion through Orowan strengthening, thereby increasing strength. The C/M-H12 composite with 12 h HEA ball milling achieves the highest ultimate tensile strength of 433.2 MPa, representing a 46.5 % improvement over C/M-H0. This enhancement originates from the combined effects of load transfer by micron-sized HEA and Orowan strengthening by nano-sized HEA. Although the C/M-H8 sample exhibits an ultimate tensile strength of 407.1 MPa, it demonstrates optimal damping performance at 0.01481, a 12.6 % increase over C/M-H0. This improvement is ascribed to the synergistic action of dislocation damping and plastic zone damping mechanisms. ... mehrThese findings indicate that tailoring reinforcement particle morphology and size through mechanical ball milling enables optimization of mechanical properties and damping performance in composites.