In-situ synthesis of MoSi{sub 2}-Al{sub 2}O{sub 3} composite by a thermite reaction
- Philip Morris, USA, Richmond, VA (United States)
- CeraMat Technologies, Oak Ridge, TN (United States)
In this paper, the authors discuss the reaction mechanism involved in the thermite reaction leading to the synthesis of a composite since in an actual combustion synthesis, the reaction propagates at a velocity of 10 to 20 mm/sec. Reaction mechanism was determined by using a differential thermal analysis (DTA) and X-ray diffraction (XRD). During the combustion synthesis of MoSi{sub 2}-{alpha}Al{sub 2}O{sub 3}, reaction of MoO{sub 3}, Al and Si occurs rapidly and the reactants and products are expected to be in the liquid state at the combustion temperature. MoO{sub 3} is first reduced to MoO{sub 2}, and the reaction between MoO{sub 2}, Al and Si leads to a composite of MoSi{sub 2}-{alpha}Al{sub 2}O{sub 3}. Differential thermal analysis reveals that the onset of exothermic reactions is preceded by melting indicating the necessity of molten Al for the synthesis of the composite. The reaction between MoO{sub 2} + 2Al +2Si can be moderated with Mo-Si mixtures such that the ratio of MoSi{sub 2} to Al{sub 2}O{sub 3} can be increased in the composite of MoSi{sub 2}-{alpha}Al{sub 2}O{sub 3}.
- OSTI ID:
- 103594
- Journal Information:
- Scripta Metallurgica et Materialia, Vol. 33, Issue 3; Other Information: PBD: 1 Aug 1995
- Country of Publication:
- United States
- Language:
- English
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