STRUCTURE AND MECHANICAL STRENGTH OF AL-V-FE MELT-SPUN RIBBONS CONTAINING HIGH-VOLUME FRACTION OF NANOSCALE AMORPHOUS PARTICLES

A new nonequilibrium structure consisting of nanoscale amorphous parti cles surrounded by fcc-Al phase was found to form in an Al94V4Fe2 allo y rapidly solidified at the condition of circumferential velocity of 4 0 mis and ejection temperature of molten alloy between 1273 and 1423 K . Deviations of the alloy component and solidification condition cause the formation of the nanoscale mixed structure of Al+icosahedral(I) p hases or Al+I+amorphous phases. The sizes of the amorphous and Al phas e regions are about 10 and 7 nm, respectively, and the volume fraction of the amorphous place region is about 60%. The formation of the nano scale amorphous particles in coexistence with Al phase is presumably d ue to the suppression of the transition from super-cooled liquid to I- phase resulting from the retardation of the diffusivity of the solute elements. The tensile strength is as high as 1400 MPa for the mixed am orphous+Al phases and decreases significantly by the transition to I+A l phases. The first success in fabricating a nano-amorphous structure is particularly important for the subsequent development of nanophase materials.