High-purity amorphous Zr_(52.5)Cu_(17.9)Ni_(14.6)Al_(10)Ti_5 powders via mechanical amorphization of crystalline pre-alloys

摘要

Fully amorphous Zr_(52.5)Cu_(17.9)Ni_(14.6)Al_(10)Ti_5 (Vit 105) powder with very low oxygen contamination was successfully produced from pre-alloyed crystalline material. A yield of over 80% was achieved without the use of a milling agent. The amorphization process was observed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The extremely fast amorphization rate was fitted by an exponential relaxation function. A partial time-temperature-transformation (TTT) diagram was obtained from isothermal annealing experiments based on the Johnson-Mehl-Avrami (JMA) model. In addition, the microstructure of the powder was observed by scanning electron microscopy (SEM), and gas analysis was conducted at various stages of the ball-milling process.