Devitrification studies of Zr–Pd and Zr–Pd–Cu metallic glasses

High temperature X-ray diffraction (HTXRD) is used to investigate the devitrification pathway for two related Zr-based metallic glasses, Zr70Pd30 and Zr70Pd20Cu10. Both alloys have similar as-quenched structures and initially devitrify to form a meta-stable quasicrystalline phase. The HTXRD data for the Zr70Pd30 alloy shows the coexistence of the quasicrystalline and the Zr2Pd (I4/mmm) crystalline phases over a range of 25 K. Conversely, the Zr70Pd20Cu10 alloy shows an additional transformation of the quasicrystalline phase to a meta-stable Zr2(PdCu) intermetallic (Zr2Si type structure, I4/mcm) that polymorphically transforms to the Zr2Ni type structure (I4/mmm) over a very narrow temperature range.