Investigations on surface morphologies, microstructure and thermal properties of tungsten-based composites

Abstract

The purpose of this research is to determine the surface morphologies, microstructural and thermal properties of tungsten-based composites that consist of 93 wt.% tungsten (W), 6 wt.% vanadium carbide (VC) and 1 wt.% graphite (C) powders. W-6 wt.% VC-1 wt.% C powders were mechanically alloyed (MA’d) for 6 hrs using a [Formula: see text] with a rate rpm using tungsten carbide vial and balls and sintered at [Formula: see text] for under [Formula: see text], [Formula: see text] gas flow conditions. The phase composition and microstructural characterization of the tungsten composites were carried out using X-ray diffractometer (XRD), Scanning Electron Microscopy (SEM) and Raman Spectroscopy. SEM images showed the distribution of the tungsten (W), vanadium carbide (VC) and graphite (C) powders and porosity in the tungsten matrix. The Raman spectra exhibited two major peaks, which are recorded at 1331 (vs) [Formula: see text] and 1583 (vs) [Formula: see text] in the Raman spectra. These bands represented carbon phases such as disordered graphite (D) and graphite (G). Thermogravimetric analysis (TGA) measurements were performed to obtain the weight loss and thermal stability of samples in the temperature range [Formula: see text]–[Formula: see text] under argon gas atmosphere. The TG curve revealed a total loss of 3.3% of weight at this temperature range. It is considered that the cause of mass loss is due to the oxidation and gas desorption of materials.