Study on Spheroidization of Niobium Powders by RF Plasma Processing

Abstract

Spherical niobium powders were synthesized by (RF) argon plasma with irregular niobium powders in this paper. The objective of the present work was to investigate how the feeding rate influence the spheroidization efficiency. The phase composition, morphology and particle size distribution of the powders before and after spheroidization were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser micron sizer (LMS). The results show that niobium powders after plasma processing have good dispersity and smooth surfaces, and their spheroidization ratio is almost 100%. The apparent density and flowability of the powder with the spheroidization efficiency 100% is 4.35 g/cm3 and 12.51 s/(50g), respectively. With the increasing of the feeding rate, the spheroidization ratio of niobium powders drops gradually.