The effect of Cu addition on the formation of f.c.c.-Al phase in rapidly quenched Al-Y-Ni alloys

The structure and microhardness of amorphous and nanocrystalline melt-spun Al88Y3Ni9 − xCux (x = 0, 2, 4, 6 at.%) alloys were examined. Variation of cooling rate controlled by the rotational wheel speed (15–60 s−1) resulted in the formation of ductile nano-composite material (x = 2, 4) composed of nanoscale f.c.c.-Al particles embedded in an amorphous matrix. The effect of replacement of Ni by Cu on structural and mechanical properties was studied. This replacement extended the temperature region in which the Al phase precipitates, causing a decrease in particle size from 50 (x = 0) to 10 nm (x = 4). The volume fraction of the nanoscale particles and lattice parameter of Al phase were calculated. Due to the nanoscale Al particles, a significant increase in microhardness compared with the amorphous single phase was observed.