Ceramic surfaces and sintering [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 1991. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- Pages: (18 pages) : digital, PDF file
- Additional Creators:
- United States. Department of Energy and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- We produced ultrafine faceted alumina particles (UFPs), 20--50 nm in diameter, by an arc-discharge method and sintered small clusters of them as they were carried through a tube furnace by flowing gas. The experiment was conducted under near UHV clean environment and specimens were examined in a UHV H9000 TEM. The UFPs produced in this study were transition alumina phases (γδ and θ). We found new δ and θ phases which were different from those in earlier studies. We developed two computer programs to simulate the shape, 3-D arrangement, and random contact of UFPs. Gaps were discovered to exist between particles due to random contact and possibly rotation and slip after contact. As no shrinkage was found, surface diffusion was identified as the dominant mechanism that was responsible for the formation of necks'' by filling in the gaps. These necks had well-defined, atomically-sharp contact angles, which suggest that the neck growth process was controlled by faceting.
- Published through SciTech Connect., 08/01/1991., "doe/er/45309-4", "DE92011570", Marks, L.D., and Northwestern Univ., Evanston, IL (United States)
- Funding Information:
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