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High-Pressure Synthesis of Metal-Ceramic Nano-CompositesThe major problems in fabrication of nano-crystal line materials form nano-powders are: (1), coarsening of the initial nano-size grains, (2), insufficient densification (high concentration of pores), and, (3), conversion of diamond into graphite (for diamond-based ceramics). We have developed a novel technique of the synthesis of nano-composite materials applying very high (up to about 10 GPa) pressures. In this technique, one component is pre-compacted and placed next to another having a lower melting point temperature. The whole sample is pressed and the temperature raised above the melting point of the second component, what results in the melt getting pressed into the (nano-size) pores of the compact. Upon subsequent crystallization the melt forms the second nanophase. The process is fast, on the order of seconds, and the temperatures are relatively low what prevents, or at least significantly reduces coarsening of the starting nanophase grains. Also, conversion of diamond into graphite can be prevented. The technique allows for control of the final product properties through a proper selection of (1) the initial compact density and grain size, (2) chemical composition of the source, and (3) the temperature and pressure of the process. The application of the technique to the synthesis of SiC and diamond with Si, Ge, and different metals. Results of the in-situ investigation of the synthesis process by synchrotron X-ray diffraction technique will be presented.
Document ID
20010048757
Acquisition Source
Marshall Space Flight Center
Document Type
Preprint (Draft being sent to journal)
Authors
Gierlotka, S.
(Polish Academy of Sciences Warsaw, Poland)
Palosz, B.
(Polish Academy of Sciences Warsaw, Poland)
Ekimov, E.
(Academy of Sciences (USSR) Troitsk, USSR)
Grzanka, E.
(Polish Academy of Sciences Warsaw, Poland)
Stelmakh, S.
(Polish Academy of Sciences Warsaw, Poland)
Lojkowski, W.
(Polish Academy of Sciences Warsaw, Poland)
Bismayer, U.
(Hamburg Univ. Germany)
Palosz, W.
(NASA Marshall Space Flight Center Huntsville, AL United States)
Rose, M. Franklin
Date Acquired
August 20, 2013
Publication Date
January 1, 2001
Subject Category
Composite Materials
Meeting Information
Meeting: Nanospace 2001
Location: Galveston, TX
Country: United States
Start Date: March 14, 2001
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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