Synthesis of nanostructured $\text{Ni}\text{Cr}$ and Ni-Cr₃C₂ powders by an organic solution reaction method

Abstract

Nanostructured nickel/chromium ($\text{Ni}\text{Cr}$) and nickel-chromium carbide (NiCr₃C₂) powders were prepared via a chemical route. The technique involves reductive decomposition of an organic solution of metal chloride precursors using sodium triethylborohydride. After co-precipitation of a nanoscale mixed metal (Ni+Cr) powder, low temperature annealing is used to form nanostructured $\text{Ni}\text{Cr}$ alloy powder, or low temperature gas phase carburization to form nanostructured Ni-Cr₃C₂ cermet powder. These powders were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and chemical analysis. The mechanisms of halide reduction and phase formation are discussed.