The fracture toughness (17.32 MPa m 1/2 and 13.66 MPa m 1/2 ) and percentage elongation (15% and 12.5%) of the 6 and 8 wt.% Cu reinforced Al-Zn composites, also surpassed that reinforced with SiC ( K IC − 12.28 MPa m 1/2 % ε f − 9.5%). Besides hardness, the strength parameters − ultimate tensile strength (149.33 MPa and 138.64 MPa) and specific strength (54.3 MPa cm ³ g ⁻¹ and 51.16 MPa cm ³ g ⁻¹ ) − of the Al-Zn composites reinforced with 6 and 8 wt.% Cu, were superior to that of the unreinforced Al-Zn alloy (103.47 MPa) and the 8 wt.% SiC reinforced composite (130.5 MPa).
The low porosity (<4%), near absence of dissolved Cu in the Al-Zn matrix, and marginal presence of melt reaction-induced intermetallic phases, attest to the soundness of the castings.
The structural characteristics, mechanical and damping properties of stir-cast Al-10 wt.% Zn based composites developed using 6 and 8 wt.% Cu, and 8 wt.% SiC particles as reinforcements, were investigated.