Influence of heterogeneous microstructure on the tensile properties of (Al2O3+AlB2)/Al composites

Abstract

In this study, the (Al2O3+AlB2)/Al composites were in–situ synthesized via chemical reactions between 90 wt% of Al and 10 wt% of B2O3 powders, followed with hot extrusion. Heterogeneous microstructures were achieved through altering the fineness of raw Al powders. The yield strength (YS), ultimate tensile strength (UTS) and elongation (EL) of the composite fabricated by 90 wt% of fine Al powder are 350 MPa, 401 MPa and 6.0%, respectively. The composite fabricated by 60 wt% of fine Al powder and 30 wt% of coarse Al powder have the best tensile properties, with the YS, UTS and EL of 372 MPa, 460 MPa and 7.2%, respectively. The YS, UTS and EL of the composite fabricated by 60 wt% of coarse Al powder and 30 wt% of fine Al powder are 335 MPa, 416 MPa and 5.1%, respectively, while it has the most attractive work hardening ability. This work may shed new lights for the design of Al based composites.