Interfacial fracture energy-mechanical behaviour relationship in Al2O3/SiC and Al2O3/TiN nanocomposites
| Autor: | R.W. Davidge, S. Jiao, Michael L. Jenkins |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Work (thermodynamics)
Materials science Polymers and Plastics Metallurgy Metals and Alloys Energy balance chemistry.chemical_element Fracture mechanics Microstructure Surface energy Electronic Optical and Magnetic Materials chemistry visual_art Ceramics and Composites visual_art.visual_art_medium Grain boundary Ceramic Composite material Tin |
| Zdroj: | Acta Materialia. 45:149-156 |
| ISSN: | 1359-6454 |
| DOI: | 10.1016/s1359-6454(96)00168-1 |
| Popis: | Grain boundary-interface dihedral angles in Al2O3/SiC and Al2O3/TiN nanocomposites have been measured from TEM micrographs, and the ratio of the particle/matrix interfacial energy γi to the alumina grain boundary energy γgb has been calculated on the basis of an energy balance condition. The average ratio, γi/γgb, was found to be 1.21 for Al2O3/SiC and 0.80 for Al2O3/TiN. These results, together with estimates of surface energies, have been used to estimate interfacial fracture energies. It is found that the interfacial fracture energy between SiC and alumina is more than twice the alumina grain boundary fracture energy, i.e. SiC nanoparticles strengthen grain boundaries. The dominant factor in this result is the greater surface energy of SiC compared with Al2O3. Despite the higher surface energy of TiN and the lower γi/γgb ratio for Al2O3/TiN, it is found experimentally that TiN particles weaken grain boundaries instead of strengthening them. The detrimental factor is believed to be the formation of TiO2 at the interfaces. The weakening is consistent with a lower interfacial fracture energy. The present work indicates the importance of interfacial properties, which should not be ignored in modelling. |
| Databáze: | OpenAIRE |
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