Effects of Ni addition on the glass-forming ability, mechanical properties and corrosion resistance of Zr–Cu–Al bulk metallic glasses

The thermal stability, glass-forming ability (GFA), mechanical properties and corrosion resistance of Zr60Cu25−xAl15Nix (x = 0–25 at.%) bulk metallic glasses (BMGs) were systematically investigated. The additional Ni greatly enhances the thermal stability and GFA of BMGs. For alloy with x = 15, a fully glassy rod with a critical diameter up to 18 mm can be obtained by copper mold casting. In addition, the strength and plasticity of BMGs are effectively improved by adding Ni, and they show remarkable correlations with glass transition temperature and Poissonʹs ratio or G/B value, respectively. A Zr60Cu5Al15Ni20 BMG exhibits largest compressive plastic strain of 5.5%, yielding strength of 1755 MPa and Youngʹs modulus of 83 GPa at ambient temperature. Moreover, the electrochemical potentiodynamic polarization curves demonstrate that replacement of Cu by Ni improves the corrosion resistance in chloride-ion-containing solutions significantly.