Amorphous and nanostructured Al 85Ni 5Y 6Co 2Fe 2 powder prepared by nitrogen gas-atomization

Abstract

Al 85Ni 5Y 6Co 2Fe 2 fully amorphous and partially amorphous powders were prepared by nitrogen gas-atomization method. The microstructure and thermal stability as a function of powder size were investigated. A majority of the powders are below 45 μm, and the content of amorphous phase is as high as 97.3% in the <25 μm size range. With the increase of particle size, the phase constituent alters from amorphous to amorphous’ + fcc-Al, then fcc-Al + AlNiY + Al 3(Ni, Fe), and finally fcc-Al + Al 9Co 2 + Al 3Y + Al 3(Ni, Fe). All of the powders show three exothermic reactions in the DSC traces, and the <25 μm size range presents a wide supercooled liquid region of 22 K and a primary crystallization temperature of 580 K. The Al 85Ni 5Y 6Co 2Fe 2 alloy powders exhibit a high microhardness of near 348 Hv, suggesting its good potential for structural application.