<Abstract>

Uniaxial compression tests were carried out on micro-pillars fabricated from

nanolaminated graphene (reduced graphene oxide, RGO)-Al composites of

different RGO concentrations and laminate orientations (the angle between

laminate planes and the pillar axis). It was found that the strengthening capability

of RGO can be enhanced by either orienting the RGO layers parallel with the

loading direction or raising the RGO concentration. The stress–strain response

of the micro-pillars was populated with discrete bursts, and the stress increments

of the bursts scaled with the RGO concentration, regardless of the laminate

orientation relative to the loading direction. These observations were interpreted

by the variation in the load-bearing capacity of RGO in different laminate

orientations, the dislocation annihilation at the RGO/Al interface, and a crack

deflection mechanism provided by the robust RGO/Al interface that toughened

the composites. This work underscores the importance of structural design and

control in the stiffening, strengthening, and toughening of metal matrix composites,

and the methodology developed may be applied to other composites with

microstructural heterogeneity to probe their specific mechanical behaviors

and structure-property correlations.

<全文連結>