Crystallization and thermal properties of Zr-AI-Cu-Ni based amorphous alloy added with boron and silicon

The amorphous Zr_65-x-yAl_7.5 Cu_17.5Ni ₁₀Si_xB_y alloy ribbons, x = 1 to 4 and y = 1 to 2, with 0.1 mm thickness were prepared by melt spinning. Both of T_g and T_x for Zr_65-x-yA_l7.5 Cu _17.5Ni₁₀Si_xB_y alloys increase with the silicon and boron additions and reaches 674 K and 754 K, respectively for Zr₆₀Al_7.5 Cu_17.5Ni₁₀Si ₄B₁ alloy. The highest T_rg (0.62) and γ value (0.43) occur at the Zr₆₀Al_7.5Cu _17.5Ni₁₀Si₄B₁ alloy. In addition, Zr₆₀Al_7.5Cu_17.5Ni₁₀Si ₄B₁ alloy was revealed to have the highest activation energy of crystallization about 370 kJ/mole, as determined by the Kissinger plot. This value is about 20% higher than the activation energy of crystallization for the Zr₆₅Al_7.5Cu_17.5Ni ₁₀) based alloy (314kJ/mole). In parallel, the alloy 4SilB also performs a longer incubation time at higher isothermally annealing temperature. All of the evidence implies that Zr₆₀Al_7.5 Cu _17.5Ni₁₀Si₄B₁ alloy exhibits the highest thermal stability among those alloy systems in this study. The detail mechanism of crystallization will be discussed in this paper.