Mechanical properties of the Mg-based amorphous/nano zirconia composite alloy

Mg-based composites are fabricated through mechanical alloying (MA) the Mg₆₅Cu₂₀Y₁₀Ag₅ amorphous alloy spun and mixed with 1-5 vol.% spherical nano-sized ZrO₂ particles in the planetary mill, after then formed by hot pressing in Ar atmosphere under different pressures at the temperature 5 K above the glass transition temperature (T_g), The microstructure characterizations of the resulting specimens are conducted by means of XRD, FEG-SEM, and TEM techniques. It is found that the nano-sized ZrO₂ dispersed Mg-based composite alloy powders can reach to a homogeneous size distribution (about 80 nm) after 50-hour mechanical alloying. After hot pressing of these composite alloy powders under the pressure of 1100 MPa at 409K, a 96% dense bulk specimen can be formed. Throughout the MA and hot pressing, the amorphous nature of the Mg ₆₅Cu₂₅Y₁₀Ags matrix is maintained. The hardness of the formed bulk Mg-based composites (with 3 vol.% nano-sized ZrO₂ particles) can reach to 370 in H_v scale. In addition, the toughness of the formed bulk Mg-based composites presents an increasing trend with the content of nano-sized ZrO₂ particles and can reach to 8.9 MPa √m.