Yuqiang Liang,Hongzhi Cheng,Yujie Zhang,Junyang Jin,Yang Wang,Jian Gu,Jian Yang,Yinsheng Li
A novel amorphous Zr-MOFs (aZMs) was synthesized using ZrCl 4 and C 10 H 6 O 8 , 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.
ZrO 2 @C spherical powder was synthesized via a solvothermal method and utilized in the fabrication of ZrC ceramics through direct ink writing (DIW) to enhance rheological properties and reduce sintering temperature. The effects of solid content on the rheological behavior and printability of the ZrO 2 @C paste were systematically investigated. The ZrO 2 @C paste exhibited typical pseudoplastic fluid characteristics and viscoelastic properties, demonstrating excellent shape retention and shear-thinning behavior. Optimal solid content and printing speed were determined to be 54 wt% and 100 mm/s, respectively, leading to superior printability. Using these optimized parameters, green bodies with planar and lattice structures were rapidly and precisely fabricated. After reactive sintering at 1600 °C, the resulting ZrC ceramic achieved a promising bending strength of 30.9 MPa. This study provides a robust strategy for the rapid fabrication of ultrahigh-temperature ceramics with complex geometries.
危险品化学品经营许可证（带存储）