Strength and Creep in Boron Carbide (B4C) and Aluminum Dodecaboride (α-AlB12)
| Autor: | T.G. Abzianidze, S.O. Shalamberidze, A.M. Eristavi |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Dislocation creep
Materials science Metallurgy chemistry.chemical_element Boron carbide Condensed Matter Physics Boron carbides Electronic Optical and Magnetic Materials Inorganic Chemistry Stress (mechanics) chemistry.chemical_compound chemistry Flexural strength Creep Aluminium Materials Chemistry Ceramics and Composites Physical and Theoretical Chemistry Deformation (engineering) Composite material |
| Zdroj: | Journal of Solid State Chemistry. 154:191-193 |
| ISSN: | 0022-4596 |
| DOI: | 10.1006/jssc.2000.8834 |
| Popis: | Some thermomechanical properties of boron carbide and aluminum dodecaboride are presented. The dependence of the bending strength on the temperature of B 4 C and AlB 12 in the ductile rupture region was studied. It was detected that the ductile rupture of B 4 C starts at temperatures above 1500°C while that of AlB 12 begins at 1400°C. Total deformation, however, did not exceed 2% even at 1800°C. The investigation of the creep of B 4 C and AlB 12 showed that the rate de / dt of steady creep depends on the applied stress and the temperature: de / dt = Aσ n exp(− E / RT ). Besides, creep in boron carbide at stress values lower than 90 MPa occurred by the vacancy-diffusive mechanism, for which n =1. At stress values over 90 MPa, n =3 and the creep mechanism changes to dislocation creep. A similar phenomenon is observed in the case of aluminum dodecaboride; however, the replacement of the vacancy-diffusive mechanism by dislocation creep takes place at stress values of 80 MPa. |
| Databáze: | OpenAIRE |
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