An Investigation of the Mechanical Properties and Fracture Characteristic of Hot-Pressed Boron Nitride Ceramics
| Autor: | Tahsin Boyraz, Burcu Ertuğ, O. Addemir |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Materials science
Scanning electron microscope Mechanical Engineering Bending Intergranular corrosion Condensed Matter Physics Hot pressing chemistry.chemical_compound Fracture toughness chemistry Mechanics of Materials Boron nitride visual_art visual_art.visual_art_medium Fracture (geology) General Materials Science Ceramic Composite material |
| Zdroj: | Materials Science Forum. 554:201-205 |
| ISSN: | 1662-9752 |
| DOI: | 10.4028/www.scientific.net/msf.554.201 |
| Popis: | The overall mechanical characterization of hot-pressed hexagonal boron nitride (h-BN) based ceramics was performed. Hardness, flexure strength and fracture toughness (KIC) measurements were carried out using Vickers indentations, 3-point bending tests and SEVNB method, respectively. The fracture characteristics of hot-pressed h-BN ceramics were investigated by analyzing fracture surfaces using scanning electron microscope (SEM). The hardness, ranged from HV = 0.20GPa to HV = 0.25GPa, which was higher in the surfaces parallel to the hot-press direction due to the perpendicular alignment of the basal planes of the h-BN platelets to the hotpress direction. The fracture toughness and flexure strength values were determined to be 2.6 MPa.m1/2 and 0.14 GPa, respectively. A single KIC value was obtained since a slight variation of the fracture toughness was observed with the orientation of h-BN. The microstructural observations of h-BN grains indicated completely brittle fracture with intergranular voids and microcracks revealing a mixed mode of fracture. |
| Databáze: | OpenAIRE |
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