Improved toughness of spark-plasma-sintered Si3N4 ceramics by adding HfB2
| Autor: | Hua-Tay Lin, Si-Chun Luo, Kevin P. Plucknett, Wei-Ming Guo |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Equiaxed crystals Toughness Materials science Process Chemistry and Technology Spark plasma sintering 02 engineering and technology 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials Fracture toughness Phase (matter) visual_art 0103 physical sciences Vickers hardness test Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Ceramic Composite material 0210 nano-technology |
| Zdroj: | Ceramics International. 47:8717-8721 |
| ISSN: | 0272-8842 |
| Popis: | High toughness and high hardness Si3N4 ceramics with fine and bimodal microstructure was prepared by combination of HfB2 additive and spark plasma sintering (SPS). HfB2-free SPSed Si3N4 ceramics at 1600 °C exhibited major α-Si3N4 phase, a fine and equiaxed grain microstructure, high Vickers hardness (21.3 ± 0.2 GPa), and low fracture toughness (3.7 ± 0.3 MPa m1/2). The introduction of 2.5 vol% HfB2 into Si3N4 ceramics at 1600 °C promoted α-to β-Si3N4 phase transformation, produced a fine and bimodal microstructure, significantly improved the toughness (7.7 ± 0.6 MPa m1/2) but slightly decreased the hardness (20.4 ± 0.6 GPa) which was higher than that of traditionally hot-pressed or pressurless sintered Si3N4 ceramics (~14–18 GPa). |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect