Dynamic deformation and fracture response of a 6061-T6 Al–50 vol. % Al[sub 2]O[sub 3] continuous reinforced composite

Abstract

In this paper results are reported on the influence of strain rate and shock loading on the deformation and fracture response of a 6061-T6 Al–50 vol. % Al2O3 continuous fiber-reinforced composite as a function of composite orientation. The stress-strain response was found to vary substantially as a function of loading orientation; the quasi-static yield changing from nominally 300 MPa transverse to the fibers to ∼1000 MPa parallel to the fibers. Increasing the strain rate to 2000 s−1 was observed to only slightly increase the yield strength of either orientation. Transverse VISAR wave profile and spall measurements revealed a small, well defined elastic precursor followed by a reasonably sharp shock rise. The failure response of the composite transverse to the fibers, under both uniaxial stress (quasistatic and dynamic) and uniaxial strain loading, display a protracted but substantial load drop after yield followed by continued degradation in load carrying capacity. Lack of ideal parallel fiber construction leads to systematic bending failure of the alumina fibers through the sample under uniaxial stress and slow spallation kinetics as various fibers fail and pull out of the matrix across the spall plane.