Hexagonal OsB2: Sintering, microstructure and mechanical properties
- Univ. of Central Florida, Orlando, FL (United States)
- Univ. of Central Florida, Orlando, FL (United States); Institute for Problems of Materials Science, Kyiv (Ukraine)
- Laboratory for High Performance Ceramics, Dubendorf (Switzerland)
- Laboratory for High Performance Ceramics, Dubendorf (Switzerland)
- Laboratory of Mechanical Metallurgy, EPFL, Lausanne (Switzerland)
- Texas A & M Univ., College Station, TX (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
In this study, the metastable high pressure ReB2-type hexagonal OsB2 bulk ceramics was produced by spark plasma sintering. The phase composition, microstructure, and mechanical behavior of the sintered OsB2 were studied by X-ray diffraction, optical microscopy, TEM, SEM, EDS, and nanoindentation. The produced ceramics was rather porous and contained a mixture of hexagonal (~80 wt.%) and orthorhombic (~20 wt.%) phases as identified by X-ray diffraction and EBSD analysis. Two boron-rich phases, which do not contain Os, were also identified by TEM and SEM/EDS analysis. Nanoindentation measurements yielded a hardness of 31 ± 9 GPa and Young’s modulus of 574 ± 112 GPa, indicating that the material is rather hard and very stiff; but, it is very prone to crack formation and propagation, which is indicative of a very brittle nature of this material. Improvements in the sintering regime are required in order to produce dense, homogeneous and single phase hexagonal OsB2 bulk ceramics.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- Grant/Contract Number:
- AC05-00OR22725
- OSTI ID:
- 1265283
- Journal Information:
- Journal of Alloys and Compounds, Vol. 634; ISSN 0925-8388
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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