Microstructure and mechanical properties of B4C based ceramics with Fe3Al as sintering aid by spark plasma sintering

B4C based ceramics were fabricated with different Fe3Al contents as sintering aids by spark plasma sintering at relatively low temperature (1700 °C) in vacuum by applying 50 MPa pressure and held at 1700 °C for 5 min. The effect of Fe3Al additions (from 0 to 9 wt%) on the microstructure and mechanical properties of B4C has been studied. The composition and microstructure of as-prepared samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalyzer (EPMA) equipped with WDS (wavelength dispersive spectrometry) and EDS. The mixtures of B4C and Fe3Al underwent a major reaction in which the metal borides and B4C were encountered as major crystallographic phases. The sample with 7 wt% of Fe3Al as a sintering aid was found to have 32.46 GPa Vickers hardness, 483.40 MPa flexural strength, and 4.1 MPa m1/2 fracture toughness which is higher than that of pure B4C.