Article Dans Une Revue Acta Materialia Année : 1999

In situ synchrotron characterization of mechanically activated self - propagating high temperature synthesis applied in Mo - Si system

Résumé

Abstract An original experiment was designed to monitor structural and thermal evolutions during the MASHS (Mechanically Activated Self-propagating High-temperature Synthesis) process in the Mo–Si system. Time-Resolved X-Ray Diffraction (TRXRD) coupled with an infrared imaging technique was performed to study, in situ, the formation of the α-MoSi2 phase in the combustion front. Despite a temporal resolution of 50 ms between two consecutive diffractograms, no intermediate phase was observed during the passage of the combustion front. The only reaction responsible for the self-sustentation is Mo+2Si→MoSi2 in the primary zone inside the combustion wave. The mechanical activation was found to influence Self-propagation High-temperature Synthesis (SHS) parameters such as the propagation front velocity (>13 mm/s), the maximal combustion temperature and the local thermal gradient. After the MASHS process, the α-MoSi2 compound is nanostructured (DMoSi2=88 nm) and some explanations are expressed in order to understand why the nanostructure of the as-milled powders can be maintained during the combustion reaction

Dates et versions

hal-00131165 , version 1 (15-02-2007)

Identifiants

Citer

C.H Gras, F. Charlot, E. Gaffet, F. Bernard, J.C Niepce. In situ synchrotron characterization of mechanically activated self - propagating high temperature synthesis applied in Mo - Si system. Acta Materialia, 1999, 47(7) (7), pp.2113 - 2123. ⟨10.1016/S1359-6454(99)00084-1⟩. ⟨hal-00131165⟩
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