Amorphous Zr-MOFs derived high-quality ZrC nanoparticles to prepare ZrC ceramics

A novel amorphous Zr-MOFs (aZMs) was synthesized using ZrCl₄ and C₁₀H₆O₈, with deionized water and ethanol as solvents. ZrC nanoparticles were successfully synthesized by pyrolyzing aZMs precursors via one-step thermal decomposition. Effects of metal/linker molar ratios and pyrolysis temperatures on the composition and microstructure of ZrC powders were investigated, meanwhile, the synthesis mechanisms were also discussed. High-purity spherical ZrC nanoparticles (104.2 ± 21.5 nm) were obtained by pyrolyzing the aZMs with metal/linker molar ratio of 2 at 1500 °C. Notably, additive-free dense ZrC ceramic were fabricated using precursor-derived ZrC nanoparticles at 1900 °C for 1 h with a pressure of 30 MPa by SPS, achieving a high relative density (96.2 %) and Vickers hardness (15.9 GPa). Compared with commercially available ZrC ceramic (93.3 %, 12.79 GPa), the as-sintered ZrC ceramic exhibited better sinterability and higher hardness. This work provides a promising potential for use in fabricating ZrC-based ultra-high temperature ceramics and composites.