The seawater corrosion resistance and mechanical properties of Cu47.5Zr47.5Al5 bulk metallic glass and its composites

• Cu47.5Zr47.5Al5 BMG and its as-cast and as-annealed composites were synthesized.
• The seawater corrosion resistance of BMG and its composites has been investigated.
• The as-cast BMG composite shows the best seawater corrosion resistance.
• The amount and distribution of precipitated phases influence corrosion resistance.
• BMG exhibits good ductility of ~ 1% and compressive fracture strength of ~ 1843 MPa.

The Cu47.5Zr47.5Al5 bulk metallic glass (BMG) and its composites have been synthesized by the copper-mold suction casting method and proper annealing treatment. The corrosion behaviors in seawater solution and mechanical properties of the BMG and its composites have been investigated by electrochemical polarization measurement, scanning electron microscopy and MTS Criterion testing machine. The results show that the as-cast BMG composite exhibits the higher corrosion potential and lower corrosion current density as well as distinct passive region. Combined with the corrosion morphologies, it suggests that the as-cast BMG composite has a higher corrosion resistance in seawater than the BMG and as-annealed composite, which is attributed to an appropriate amount of CuZr nanocrystals dispersing homogeneously in the glassy matrix. Compared to its composites, the Cu-based BMG with fully amorphous structure exhibits good ductility of ~ 1% plastic elongation and high compressive fracture strength of ~ 1843 MPa.