Synthesis of tribological WS 2 powder from WO 3 prepared by ultrasonic spray pyrolysis (USP)

Abstract

This paper describes the synthesis of tungsten disulfide (WS 2 ) powder by the sulfurization of tungsten trioxide (WO 3 ) particles in the presence of additive potassium carbonate (K 2 CO 3 ) in nitrogen (N 2 ) atmosphere, first at lower temperature (200 ◦ C) and followed by reduction at higher temperature (900 ◦ C). In addition, the ultrasonic spray pyrolysis of ammonium meta-tungstate hydrate (AMT) was used for the production of WO 3 particles at 650 ◦ C in air. The HSC Chemistry® software package 9.0 was used for the analysis of chemistry and thermodynamic parameters of the processes for WS 2 powder synthesis. The crystalline structure and phase composition of all synthesized powders were analyzed by X-ray diffraction (XRD) measurements. The morphology and chemical composition of these samples were examined by scanning electron microscopy (SEM) combined with energy dispersive X-ray analysis (EDX).