Amorphization in mechanically alloyed (Ti, Zr, Nb)–(Cu, Ni)–Al equiatomic alloys

Phase formation by mechanical alloying in (Ti, Zr, Nb)–(Cu, Ni)–Al equiatomic alloys has been investigated. The structural features and the thermal stability were characterized by X-ray diffraction, transmission electron microscopy and differential scanning calorimetry. An amorphous phase forms when the (Ti, Zr, Nb) content is between 20 and 60 at.%. In contrast, solid solutions of Cu and (Nb, Zr) phase dominate in the final product with (Ti, Zr, Nb) content of 10 and ≥70 at.%, respectively. All amorphous phases have a large supercooled liquid region of over 125 K, indicating a high thermal stability against crystallization. Miedema's model is used to calculate the glass-forming range in this multicomponent alloy system. The calculated region coincides well with the experimental results.