Relationship between relaxation embrittlement and atomic cluster structure in amorphous alloys

Relationship between relaxation embrittlement and atomic cluster structure was explored by simulation and experimental methods for two amorphous alloys: Zr ₆₀Cu ₃₀Al ₁₀ and Zr ₅₀Cu ₄₀Al ₁₀ (referred to as Zr ₆₀ and Zr ₅₀, respectively). Simulation results from large-scale molecular dynamics revealed that the Zr ₅₀ alloy exhibited a higher content of icosahedral clusters, which increased more obvious during the quenching process compared to the Zr ₆₀ alloy. As icosahedral clusters exhibit brittleness similar to quasicrystalline structures, we predicted that the Zr ₅₀ alloy would have a higher glass transition temperature T _g and more pronounced relaxation-induced brittleness than the Zr ₆₀ alloy based on this observation. To validate the predictions, experimental results confirmed the occurrence of relaxation brittleness in Zr ₅₀ and relaxation non-brittleness in Zr ₆₀, consistent with the XRD analysis and electron microscope-based three-dimensional reconstruction in terms of icosahedral clusters. The agreement between the simulation calculations and the experimental data provides a reference for understanding the mechanism of relaxation embrittlement in amorphous alloys.