Formation and properties of Zr48Nb8Cu14Ni12Be18 bulk metallic glass Original Research Article

Zr48Nb8Cu14Ni12Be18 bulk metallic glass (BMG) with excellent glass-forming ability was prepared by water quenching method. The BMG exhibits high glass transition temperature Tg and onset crystallization temperature Tx, compared with Zr41Ti14Cu12.5Ni10Be22.5 BMG. The crystallization processes, change of elastic constants, and density and hardness in the crystallization process were studied by using X-ray diffraction, differential scanning calorimetry and acoustic method. The shear modulus, Poisson ratio, density and hardness are found to be sensitive to the crystallization process. A striking softening of long-wavelength transverse acoustic phonons in the BMG relative to its crystallized state is observed. The linear expansion coefficient, determined by a dilatometer method, is αTG=1.04×10−5 K−1 (300–656 K) for the BMG and αTC=1.11×10−5 K−1 (356–890 K) for the crystalline alloy. The Mie potential function and the equation of state of the BMG are determined from the expansion coefficient and acoustic experiments.