Effect of B4C particle size and TiB ₂ content on the mechanical properties of B4C composites and their dynamic mechanical properties

Abstract B ₄ C–MAS and B ₄ C–TiB ₂ –MAS ceramic composites were prepared by hot pressed sintering. The effects of particle size of B ₄ C and TiB ₂ content on the microstructure and general mechanical properties of the ceramic composites were investigated by using X‐ray diffractometer, scanning electron microscope, and universal testing machine. The strengthening and toughening mechanism of ceramic composites is mainly attributed to the addition of magnesium–aluminosilicate (MAS) and thermal mismatch effect of TiB ₂ . When the TiB ₂ content was 20 wt.%, the bending strength, fracture toughness, and Vickers hardness of B ₄ C–TiB ₂ –MAS ceramic composites were 375 MPa, 4.42 MPa·m ^1/2 , and 23.9 GPa, respectively, and its relative density could reach 99.7%. The dynamic mechanical properties of B ₄ C–TiB ₂ –MAS ceramic composites were investigated at strain rates of 2000–6000 s ⁻¹ using a Separate Hopkinson Pressure Bar (SHPB) device. The results showed that the B ₄ C–TiB ₂ –MAS ceramic composites exhibited significant strain rate sensitivity. The dynamic compressive strength of the ceramic composites increased from 4634 to 5734 MPa with increasing strain rate in the tested strain rate range.