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Microstructure evolution, densification behavior and mechanical properties of nano-HfB2 sintered under high pressure
- Source :
- Ceramics International. 45:7885-7893
- Publication Year :
- 2019
- Publisher :
- Elsevier BV, 2019.
-
Abstract
- A series of pure HfB2 ceramics have been prepared by sintering nano-grained powder using high-energy ball milling at 700–1600 °C and 5.5 GPa. The HfB2 ceramics are characterized via various techniques for their residual stress, grain size, density, microstructures and defects, hardness, fracture toughness, thermal stability, and oxidation resistance. All properties strongly depend on the treatment temperature, but the exact manner of dependence for each property varies. The results identified that the HfB2 ceramic sintered at a relatively low temperature of 1000 °C and 5.5 GPa – a bulk pure nano-grained composite for the first time – has the best overall performance. It has a relative density of 99.6%, a Vickers hardness of 26 GPa, a fracture toughness of 5.2 MPa m1/2, and excellent thermal stability and oxidation resistance at high temperatures. Additional strengthening and stabilizing effects are provided by microstructures and defects such as large-angle grain boundaries, stacking faults and twinning. Simultaneous high temperature and high pressure is an effective sintering route for HfB2 ceramics with grain-size ranging from nanometer to micron.
- Subjects :
- 010302 applied physics
Materials science
Process Chemistry and Technology
Sintering
02 engineering and technology
021001 nanoscience & nanotechnology
Microstructure
01 natural sciences
Grain size
Surfaces, Coatings and Films
Electronic, Optical and Magnetic Materials
Fracture toughness
visual_art
0103 physical sciences
Vickers hardness test
Materials Chemistry
Ceramics and Composites
visual_art.visual_art_medium
Grain boundary
Ceramic
Composite material
0210 nano-technology
Ball mill
Subjects
Details
- ISSN :
- 02728842
- Volume :
- 45
- Database :
- OpenAIRE
- Journal :
- Ceramics International
- Accession number :
- edsair.doi...........03697df420de816f4baceb2f9612877d