Investigating mechanical properties of WAlB MAB phase synthesized via spark plasma sintering

Abstract

This study investigates the synthesis and characterization of WAlB ceramics produced via spark plasma sintering (SPS). High-purity tungsten (W), aluminum (Al), and boron (B) powders were mixed and subjected to SPS at 700 °C under a constant pressure of 30 MPa for different dwell times. The phase composition and microstructural evolution of the sintered samples were analyzed using X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS). The results indicate that WAlB forms as the primary phase, with residual metallic W diminishing as the dwell time increases. SEM analysis reveals a reduction in porosity and an increase in densification with prolonged dwell times, which supports the phase transformation observed in the XRD patterns. Hardness measurements indicate that the obtained WAlB ceramics exhibit lower hardness values than those reported for single-crystal WAlB, which is attributed to incomplete densification and residual metallic W. The formation of cracks around indentation marks suggests brittleness and structural heterogeneity. The findings highlight the influence of sintering parameters on phase evolution and mechanical properties, providing insights into optimizing the synthesis of WAlB ceramics.