Preparation of Ultrafine Tungsten-Based Alloy Powders by GNP-Reduction Method

Abstract

A novel glycine-nitrate process (GNP)-reduction method has been developed to fabricate ultrafine tungsten heavy alloy powders, with ammonium metatungstate (AMT), iron nitrate nonahydrate (Fe (NO3)3·9H2O), nickel nitrate hexahydrate (Ni (NO3)2·6H2O) as raw materials and gylcine as a complexant and incendiary agent. Precursor powders were obtained by self-propagation reaction in a suspension containing above materials. The precursor powders were then hydrogen-reduced to obtain composite powders with 90W-7Ni-3Fe composition (wt.%). Phase constitution and morphology of the precursor powders and the reduced powders were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). Chemical composition of resultant powders was analyzed by energy dispersive spectrometer (EDS) analysis. It was shown that the GNP-reduction method produces ultrafine 90W-7Ni-3Fe powders with particle size of about 200 nm and highly dispersion of the composition.