TEM Studies Of Devitrification Products in Al-Gd-Ni-(Fe) Alloys

摘要

Metallic glasses can form in certain Al-Gd-Ni alloys. Devitrificaion occurs on subsequent heating to intermediate temperatures and although some phases form 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 a-Al, binary AbGd, and ternary phases. An Al-(Gd,Fe)-Ni phase forms as rods and exhibits the orthorhombic AlujNijGd.i structure. Plates of the rhombohedral phase Ai23(Ni,Fe)6Gd4 are also present. Complex faulting is observed in both ternary phases.