Grain growth in a nanocrystalline Ni81P19 alloy

Isothermal annealing of a Ni81P19 amorphous alloy performed at 600 K for 12 00 a resulted in the formation of a nanocrystalline state with 10 nm averag e grain size. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) measurements were performed to study the influence of further heat t reatments. Linear-heating DSC scan starting from the nanocrystalline state revealed a broad exothermic contribution between 600 K and 770 K correspond ing to a grain-growth process. Isothermal annealing of the nanocrystalline alloy yields the complete formation of fcc-Ni and Ni3P phases. This process took place by normal grain-growth at low annealing temperature, while abno rmal grain-growth was observed with increasing annealing temperatures. (C) 2000 Acta Metallurgica Inc.