Enhancement of Mechanical Properties and Corrosion Resistance in Zr-Based Bulk Metallic Glasses by Nanocrystal precipitation

Zr-based bulk metallic glasses (BMGs) exhibit an excellent combination of properties, including high strength, high hardness, excellent corrosion resistance and biocompatibility, which makes them a promising material for use in medical applications. Nevertheless, the lack of room-temperature plasticity has constituted a significant obstacle to its implementation. In this study, Zr₆₁Cu₁₈Al₉Ni₇Ti₅ BMGs were prepared by vacuum arc melting, and the impact of isothermal annealing treatments of varying durations (5–120 min) at 523 K on its properties was investigated. The results demonstrated that brief annealing periods, particularly 15 minutes, markedly enhanced the fracture strength (from 1607.9 MPa to 1755.7 MPa) and plasticity (from 3.4% to 11.1%) of the BMGs, while also improving their corrosion resistance, passivation interval extended to 1.344 V. This improvement can be attributed to the precipitation of nanocrystals (AlZr₂ and CuZr), which optimizes the shear band structure and promotes the formation of ZrO₂ passivation films. Nevertheless, extended annealing periods result in a decline in performance. This work offers an effective heat treatment optimization strategy for Zr-based BMGs, which have a wide range of potential applications in the medical field.