Crystallization products of amorphous Zr–Cu–Ni alloy

Abstract

The final crystallization products of the amorphous Zr 70Cu 20Ni 10 alloy were identified by employing the differential scanning calorimetry (DSC), X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM). It is noted that there still exists a face-centered cubic Zr 2Ni (f.c.c.-Zr 2Ni) phase during crystallization of the amorphous Zr 70Cu 20Ni 10 alloy upon heating up to 600 °C in spite of the metastable characteristics of the f.c.c.-Zr 2Ni phase thermodynamically. On the basis of the experimental results, it is deduced that the final crystallization products of the amorphous Zr 70Cu 20Ni 10 alloy consist mainly of the b.c.t.-Zr 2Cu and f.c.c.-Zr 2Ni phases. As for the distribution of these two crystalline phases, the primary b.c.t.-Zr 2Cu particles with a larger grain size are precipitated from the amorphous matrix first, occupying the main part of the amorphous matrix. The nanoscale f.c.c.-Zr 2Ni particles with an average grain size of about 20–30 nm are formed among the b.c.t.-Zr 2Cu particles. HRTEM observation also confirms that there exist two different areas, which correspond to the (213) plane of the b.c.t.-Zr 2Cu phase and (531) plane of the f.c.c.-Zr 2Ni phase, respectively.