High strength particulate aluminum matrix composite design: Synergistic strengthening strategy

Abstract

Aluminum-alumina (Al–Al2O3) composites with ultrahigh strength were designed by combining dispersion strengthening via the addition of Al2O3 particles and matrix strengthening via in situ strain hardening. Cold spraying additive manufacturing technology was applied to fabricate the composites. The yield strength (σ0.2%) of the Al-46 wt% Al2O3 composite was 317.4 MPa and was among the highest value reported in the literature, to the best of our knowledge, for a pure Al-based Al–Al2O3 composite. Experimental evaluation of the material showed that the compressive failure mode of the composite changed from gradual plastic collapse to shear-dominated behavior as the percentage of Al2O3 was increased or the matrix was pre-strain strengthened in the Al–Al2O3 composite.