TEM studies of devitrification products in Al-Gd-Ni-(Fe) alloys.

Metallic glasses can form in certain Al-Gd-Ni alloys. Devitrificaion occurs on subsequent beating to intermediate temperatures and although some phases from as expected the crystal structures of others are less certain. This paper presents a summary of transmission electron microscopy (TEM) data acquired from four devitrified Al-Gd-Ni(-Fe) alloys. It is shown that the alloys exhibit nanocrystalline microstructures consisting of face-centered-cubic alpha-Al, binary Al3Gd, and ternary phases. An Al-(Gd,Fe)-Ni phase forms as rods and exhibits the orthorhombic Al19Ni5Gd3 structure. Plates of the rhombohedral phase Al-23(Ni,Fe)(6)Gd-4 are also present. Complex faulting is observed in both ternary phases.