High-temperature strength of directionally reinforced LaB6–TiB2 composite

A directionally solidified eutectic LaB6–TiB2 composite was prepared by the floating zone method based on the crucible-free zone melting of compacted powders. TiB2 and LaB6 powders were used as the initial materials. The bending strength of the melted eutectic LaB6–TiB2 composite was evaluated in the temperature range of 1000–1600 °C and reached 470 MPa at 1400 °C. We speculate that the bending strength of the directionally reinforced LaB6–TiB2 composite at high temperatures mainly depends on the plasticity of the TiB2 fibers and LaB6 matrix. By analyzing the dislocation structure of the fibers, the occurrence of strain hardening in monocrystalline titanium diboride during high-temperature deformation was revealed.