SYNTHESIS OF NANOSTRUCTURED NI CR AND NI-CR3C2 - POWDERS BY AN ORGANIC SOLUTION REACTION METHOD/

Nanostructured nickel/chromium (Ni/Cr) and nickel-chromium carbide (Ni -Cr3C2) powders were prepared via a chemical route. The technique invo lves 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 u sed reform nanostructured Ni/Cr alloy powder, or low temperature gas p hase carburization to form nanostructured Ni-Cr3C2 cermet powder. Thes e powders were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and che mical analysis. The mechanisms of halide reduction and phase formation are discussed. Copyright (C) 1996 Acta Metallurgica Inc.