Microstructure and thermal analysis of amorphous Al 87RE 8Ni 5 and Al 92RE 4Ni 4 alloys

Abstract

Ternary Al-Ni rare earth (RE) amorphous alloys, Al 87RE 8Ni 5 and Al 92RE 4Ni 4 (at%), with superior bending ductility, were produced by melt-spinning in air. For the ribbons, 50–60 μm thick, the Al 87RE 8Ni 5 alloy was found to be amorphous with no trace of crystallinity, whereas the Al 92RE 4Ni 4 alloy ribbon was amorphous on the wheel side, amorphous containing finely dispersed (α-Al particles (about 5 nm in diameter) in the ribbon core, and material with an (α-Al micrograin structure, with grain size of 15–20 nm, in the free side. Amorphous Al 87RE 8Ni 5 and Al 92RE 4Ni 4 alloys all possess a very wide temperature span for the supercooled liquid, ( ΔT x = 53 and 83 K respectively, and a distinct glass forming ability with T g T m = 0.56 and 0.59 respectively.