Preparation and characterization of scandia-doped tungsten powders prepared by a spray-drying method

Abstract

Scandium oxide-doped tungsten powders were prepared by a new method of spray drying combined with two-step hydrogen reduction. The particle size of doped tungsten, powder morphology, and distribution of doped scandium oxide were characterized by scanning electron microscopy, X-ray diffraction, and laser diffraction particle size analysis. Experimental results indicated that the predecessor powders prepared by spray drying were spherical in shape. Two compounds, WO3 and Sc2W3O12, in the raw powder calcined at 600 °C were transformed into metallic tungsten and scandia after reduction at 850 °C by hydrogen for 1 h. The scandia-doped tungsten powders obtained had an average size of 950 nm and scandium oxide was distributed evenly throughout the tungsten powder. The mechanism of reduction of the doped tungsten oxide is discussed in this paper.