High-Purity, Uniform, and Spherical Hafnium Carbide Nanoparticles Derived from a Novel Amorphous Hafnium-Based Metal–Organic Framework Precursor for the Preparation of High-Performance Ceramics.
Saved in:
| Title: | High-Purity, Uniform, and Spherical Hafnium Carbide Nanoparticles Derived from a Novel Amorphous Hafnium-Based Metal–Organic Framework Precursor for the Preparation of High-Performance Ceramics. |
|---|---|
| Authors: | Cheng, Hongzhi1,2 (AUTHOR), Gu, Jian1,2 (AUTHOR), Kan, Siyuan1,3 (AUTHOR), Xie, Ran1,4 (AUTHOR), Li, Quan1 (AUTHOR), Zhang, Sinuo2,3 (AUTHOR), Jin, Junyang1,2,3 (AUTHOR), Wang, Yang1,2,4 (AUTHOR), Yang, Jian1,2 (AUTHOR), Wang, Chang-An4 (AUTHOR) |
| Source: | Materials (1996-1944). May2026, Vol. 19 Issue 9, p1754. 22p. |
| Subjects: | Metal-organic frameworks, Carbides, Nanocrystal synthesis, Ceramics, Nanoparticles, Sintering, Refractory materials, Pyrolysis |
| Abstract: | Highlights: A novel amorphous Hf-MOF precursor was synthesized via a simple and efficient method. Pure, spherical HfC nanoparticles (44.30 ± 9.63 nm) were synthesized via 1500 °C pyrolysis. HfC synthesized at 1700 °C showed low oxygen (0.76%) and near-theoretical carbon (6.42%). SPS-sintered HfC achieved 96.7% density and 20.2 GPa hardness, outperforming commercial HfC. A novel amorphous Hf-MOFs precursor was successfully synthesized and converted into HfC nanoparticles via one-step pyrolysis. The effects of metal/ligand molar ratios, solvent types, and pyrolysis temperature were systematically studied. High-purity spherical HfC nanoparticles (44.30 ± 9.63 nm) were obtained at 1500 °C using a 1.5:1 metal/ligand molar ratio with mixed anhydrous ethanol/deionized water solvents. At a pyrolysis temperature of 1700 °C, the as-synthesized HfC nanoparticles possessed an exceptionally low oxygen content of 0.76%, alongside a carbon content of 6.42% that almost perfectly matches the theoretical value of stoichiometric HfC. The formation mechanism involving Hf-O-C coordination and carbothermal reduction was clarified. Additive-free HfC ceramics were fabricated using the as-synthesized HfC nanoparticles via spark plasma sintering (1950 °C, 30 MPa, 20 min). The resulting ceramics exhibited a relative density of 96.7% and a Vickers hardness of 20.2 GPa, both of which are significantly superior to those of ceramics sintered from commercial HfC powders under identical conditions (95.8% and 17.8 GPa, respectively). This work provides a promising and feasible pathway for the preparation of other high-quality ultra-high temperature hafnium-based carbide powders and ceramics. [ABSTRACT FROM AUTHOR] |
| Copyright of Materials (1996-1944) is the property of MDPI and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
|
Full text is not displayed to guests.
Login for full access.
|
|
| Abstract: | Highlights: A novel amorphous Hf-MOF precursor was synthesized via a simple and efficient method. Pure, spherical HfC nanoparticles (44.30 ± 9.63 nm) were synthesized via 1500 °C pyrolysis. HfC synthesized at 1700 °C showed low oxygen (0.76%) and near-theoretical carbon (6.42%). SPS-sintered HfC achieved 96.7% density and 20.2 GPa hardness, outperforming commercial HfC. A novel amorphous Hf-MOFs precursor was successfully synthesized and converted into HfC nanoparticles via one-step pyrolysis. The effects of metal/ligand molar ratios, solvent types, and pyrolysis temperature were systematically studied. High-purity spherical HfC nanoparticles (44.30 ± 9.63 nm) were obtained at 1500 °C using a 1.5:1 metal/ligand molar ratio with mixed anhydrous ethanol/deionized water solvents. At a pyrolysis temperature of 1700 °C, the as-synthesized HfC nanoparticles possessed an exceptionally low oxygen content of 0.76%, alongside a carbon content of 6.42% that almost perfectly matches the theoretical value of stoichiometric HfC. The formation mechanism involving Hf-O-C coordination and carbothermal reduction was clarified. Additive-free HfC ceramics were fabricated using the as-synthesized HfC nanoparticles via spark plasma sintering (1950 °C, 30 MPa, 20 min). The resulting ceramics exhibited a relative density of 96.7% and a Vickers hardness of 20.2 GPa, both of which are significantly superior to those of ceramics sintered from commercial HfC powders under identical conditions (95.8% and 17.8 GPa, respectively). This work provides a promising and feasible pathway for the preparation of other high-quality ultra-high temperature hafnium-based carbide powders and ceramics. [ABSTRACT FROM AUTHOR] |
|---|---|
| ISSN: | 19961944 |
| DOI: | 10.3390/ma19091754 |
