Examination of kinetic components (pressure and time) of spark plasma sintering on the mechanical properties of WC/W FGM

Spark plasma sintering (SPS) is one of the new methods in powder metallurgy which has made significant progress over the past two decades and has attracted plenty of attention from researchers and industries. Recently, given the high capabilities of the SPS method, its use for manufacturing functional materials (FGM) has also sparked great research interest. Considering the studies conducted and the limitations of tungsten alloys as well as tungsten carbide alone in applications such as high-energy penetrants in the oil and gas industries along with friction stir welding tools, W/WC FGM samples have been manufactured using the SPS method for the first time in this study to enhance mechanical properties. The aim of this study is to examine the effect of the factors of pressure and time of SPS sintering on the microstructural properties of W/WC FGM. The phase, elemental, and structural properties of the powder, cross-sectional area, and fracture surface of the SPS samples, after the experiments, were characterized using X-ray diffraction and scanning electron microscopy images. The results revealed that the best sintering conditions for creating W/WC FGM bulk with the best mechanical properties included sintering the sample for 15 min, a pressure of 60 MPa, a temperature of 1400 °C, and a heating rate of 200 °C/min. In the optimal case, the W/WC FGM sample consisted of five layers with different chemical compositions and a microstructure without a diffusion zone, with tensile and flexural strengths of 745 and 890 MPa, respectively, and a density of 92.5%.