ISSN:
1662-0356
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Natural Sciences in General
,
Technology
Notes:
Combustion synthesis techniques have been applied to an equiatomic mixture ofAluminium, Nickel, Titanium and Carbon powders in order to obtain NiAl/TiC composites. Bothcombustion modes have been used: the Self-propagating High-temperature mode (SHS), in whichthe reaction propagates through the sample under the form of a heat wave and the ThermalExplosion mode (TES), in which the reaction occurs simultaneously in the complete sample. Thereactions have been followed in-situ by time-resolved diffraction, using synchrotron X-rays for theSHS mode and neutrons for the TES mode. Scanning Electron Micrographs and X-ray diffractionpatterns of the final product have shown that the same final products were obtained when themixture was synthesised under both combustion modes: a composite made of small and round TiCparticles (~1 micron) embedded into a matrix of larger NiAl grains (5 microns). However, theTime-Resolved Diffraction studies have shown that, even with the same final products, the twocombustion modes follow two completely different routes. Thus, for the SHS mode, the reaction istriggered by the formation of Nickel Aluminide and 3 intermediate phases are observed, and for theTES mode, the self-sustained reaction starts with the formation of Titanium Carbide and nointermediate phases have been seen
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/42/transtech_doi~10.4028%252Fwww.scientific.net%252FAST.45.1029.pdf
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