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: Al(88)sNi(x/2)Pd(x/2)Y(12-x) (x=2, 5, 10), Al(88)sNi(1)Co(1)Y(10-x)La(x) (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 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 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. (c) 2006 Elsevier B.V. All rights reserved.