Amorphous and nanocrystalline Al82Ni10Y8 alloy powder prepared by gas atomization

An Al-10Ni-8Y (at.%) alloy was atomized by Ar gas and the morphology, microstructure, thermal stability, phase composition and microhardness of the as-atomized powder were investigated. Most of the powders are spherical in shape, but the surface morphology was different for powder of different size. The cross-section microstructure of powder with size below 15 μm in diameter showed no detailed feature, indicating existence of amorphous phase or nanocrystalline structure. The as-atomized powder showed four distinct exothermic peaks when heated at 296, 340, 366 and 456 °C. The glass transition temperature Tg, crystallization temperature Tx, and the temperature interval of the supercooled liquid region ΔTx (=Tx−Tg) were detected to be about 266, 288 and 22 °C. The Al82Ni10Y8 alloy powder exhibits a high Vickers hardness of 230.6, and shows great potential for structural application.