Development of rapidly solidified Al–Y–Ni-based alloys

The present study is concerned with the effect of alloying additions (e.g. Co, Nb, Pd, La and Y) to the glass forming ability (GFA) of Al–Y–Ni alloys. Rapidly solidified ribbons of the following systems have been prepared by melt-spinning process: Al88Nix/2Pdx/2Y12−x (x = 2, 5, 10), Al88Ni1Co1Y10−xLax (x = 0, 5, 10), Al88Ni1Nb1Y10, and Al86Ni4−xCoxY10 (x = 1, 2, 3). Characterisation of the melt spun alloys was carried out through a combination of X-ray diffractometry, differential scanning calorimetry, and transmission electron microscopy. GFA in Al88Ni1TM1Y10 (where TM = Co, Nb, Pd) increases in the following order: Nb < Co < Pd. To maintain a fully amorphous structure in Al88–Ni–Pd–Y systems the optimum quantity of yttrium is 10 at.%. A complete substitution of Y with La, or aluminium with 2 at.% of (Co,Ni) decreases the glass forming ability in Al88Ni1Co1Y10 but increases thermal stability of the residual amorphous phase. Partial replacement of Y with La significantly improves the thermal stability of the amorphous phase in Al–Ni–Co–Y.