Stiffening of sub-micro-porous silver membranes under tensile deformation

Tensile testing of porous silver membranes is used to assess the postulate that the onset of plasticity corresponds with a shear type of deformation. The filament size and porosity take the parametric roles of feature size and free volume that are used to characterize the strain rate sensitivity of strength in nanoscale metals as now adapted for porous membranes. Experimental measurements indicate the porous membranes stiffen under tensile loading as plastic deformation progresses, as evidenced by an increase in the elastic modulus from a value consistent with the C′ elastic constant towards the C44 elastic constant.

► Assess the stiffness behavior of silver with strain hardening. ► Porous and dense silver foils are tested with interrupted tensile testing. ► Different rates of strain are used to do the interrupted tests. ► The elastic modulus increases under tensile loading as plastic deformation progresses.