Mechanical Alloying and Sintering of Ni-Sn and Ni-Mg Powder Mixtures

Various intermetallics can be synthetized by mechanical alloying depending on alloy composition, type of mill, and milling parameters. This work discusses on the phase transformations during ball milling and subsequent sintering of Ni-Sn and Ni-Mg powder mixtures. The structural evaluation of as-milled and sintered samples was conducted by X-ray diffraction and scanning electron microscopy. Metastable phases were formed during milling of the Ni-Sn and Ni-Mg powder mixtures. The Ni3Sn and Ni3Sn2 compounds were produced after sintering from the as-milled Ni-25Sn and Ni-40Sn powders, respectively. Two-phase Ni2Mg+NiMg2 alloy was found after sintering of as-milled Ni-66Mg powders because the nominal Mg amount in starting powders was reduced due to its preferential cold welding during milling and/or evaporation during sintering.