Microstructure and ablation behavior of Zr-Ti-Si-C multiphase coating fabricated by solid solution and in-situ reaction

Highlights: • The (Ti_xZr_1−x)₃SiC₂ phase is generated by solid solution and in-situ reaction to reinforce the UHTC coating. • The solid solution structure can densify and homogenize phases distribution of coating. • The (Ti_xZr_1−x)₃SiC₂ reduces the active oxidation of Si source comparing to SiC. • A strengthened ZrO₂-ZrTiO₄-TiO₂-SiO₂ layer contributes to the excellent ablation resistance of coating. • The added TiC plays a positive joint function on the long-term anti-ablation property of coating. The Zr-Ti-Si-C solid solution coatings were fabricated by solid solution and in-situ reaction methods, and effects of TiC on the microstructure and phase evolution, and ablation behavior of Zr-Ti-Si-C solid solution coatings were investigated. Results show that TiC was reacted with zirconium or silicon compounds to generate even-distributed ternary Zr_xTi_1−xC and quaternary (Ti_xZr_1−x)₃SiC₂ solid solution. The solid solution structure decreases the active oxidation of Si source, and reduces the depletion and evaporation of SiO₂, forming a strengthened ZrO₂-ZrTiO₄-TiO₂-SiO₂ oxides layer with low oxygen diffusion coefficient, thereby enhancing the ablative property of the Zr-Ti-Si-C solid solution coatings.