Analysis of the high-temperature flexural strength behavior of B_4C-TaB_2 eutectic composites produced by in situ spark plasma sintering

摘要

In this study, flexural strength measurements and microstructural studies have been combined to evaluate the effect of elevated temperatures on the fracture behavior of B_4C-TaB_2 ceramic composites that have a eutectic structure. Mechanical characterization was carried out at 1600 ℃, 1800 ℃ and 2000 ℃. The B_4C-TaB_2 eutectic composites were prepared in situ using a spark plasma sintering technique. The eutectic composites exhibited strengths of 483 ± 17 MPa and 525 ± 12 MPa at 1600 ℃ and 1800 ℃, respectively, which is higher than the strength of 430 ± 25 MPa measured at room temperature. The flexural strength of the B_4C-TaB_2 eutectic composites was 511 ± 16 MPa at 2000 ℃ (i.e. 0.86 of the melting point of the B_4C-TaB_2 eutectic), indicating plastic behavior. Analyses of the high-temperature flexural strength behavior of this non-oxide eutectic are reported.