Properties of TiB₂–PSO modified SiHfBCN-based adhesive through polymer-derived-ceramic route

High temperature SiHfBCN-based ceramic adhesives are fabricated by polymer derived ceramic route with SiHfBCN precursors, TiB₂ and polysiloxane (PSO). The phase composition and microstructure were investigated by X-ray diffraction and scanning electron microscopy, respectively and the evolution of pores was analyzed by Micron X-ray 3D Imaging System and VG Studio MAX 3.0.2 software. After heat-treating at 80 °C and curing at 170 °C in air, the adhesion strength detected in air of SiHfBCN adhesives is 3.22 MPa at room temperature (RT) and can rise to 5.47 MPa at 1000 °C after pyrolysis at 1000 °C in air for 2 h with a universal testing machine. By modifying SiHfBCN with TiB₂–PSO, the adhesion strength can be enhanced to 9.49 MPa at RT and 6.37 MPa at 1000 °C. The results indicate that the formation of SiO₂–B₂O₃–TiO₂ ternary glasses play an important role in improving the adhesion strength. The present study broaden the high temperature adhesive family suitable for large-scale complex ceramic components in harsh environments.