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

Abstract

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: Al 88Ni x/2 Pd x/2 Y 12− x ( x = 2, 5, 10), Al 88Ni 1Co 1Y 10− x La x ( x = 0, 5, 10), Al 88Ni 1Nb 1Y 10, and Al 86Ni 4− x Co x Y 10 ( 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 Al 88Ni 1TM 1Y 10 (where TM = Co, Nb, Pd) increases in the following order: Nb < Co < Pd. To maintain a fully amorphous structure in Al 88–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 Al 88Ni 1Co 1Y 10 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.