Development of B4C-HfB2 composites by reaction hot pressing

► Reaction hot pressing of B4C and HfO2 yielded full dense, high strength (7.07 MPa.m1/2 for 8.8%HfB2) B4C-HfB2 composite. ► B4C-HfB2 composite exhibits high elastic (525 GPa) and shear moduli (196 GPa). ► It proved to be an efficient technique for the fabrication of high dense B4C-HfB2 composite at a lower temperature. ► It also eliminates separate synthesis step of HfB2, thus advantages of reduced cost and time. ► Microstructural observations reveal crack deflection, arrest and bridging as major toughening phenomena in the composites.