Combustion synthesis of metal-matrix composites. Part 3: The Al-TiC-Al{sub 2}O{sub 3} system
- UFRGS, Porto Alegre, Rio Grande do Sul (Brazil). Dept. de Metalurgia
- Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering
The principle of combustion synthesis to produce metal matrix composites has been outlined in earlier papers. Applying pressure either during or immediately after the reaction is completed is the most commonly used method to achieve high densification of the synthesized products. Some advanced ceramics (TiC and TiB{sub 2}) have been reported to achieve up to 95% of theoretical density using this technique. The current research is a continuation of the work on the TiC-Al{sub 2}O{sub 3}-Al system, in which an excess amount of liquid aluminum is generated by the exothermic reaction and infiltrates the pores of the ceramic matrix improving the densification of the product. The current research is aimed at synthesizing high volume fractions, i.e., > 50%, metal matrix composites using the SHS reaction. The stability of this reaction is inversely proportional to the excess amount of the metal phase added to the reactants, i.e. xAl. The excess Al acts as a diluent, taking heat from the reaction front, and making it difficult to ignite and/or sustain the reaction in pellets with stoichiometries of high volume fractions of metal. For this reason, the simultaneous combustion (thermal explosion) mode was chosen to perform the synthesis reaction and in which the whole pellet is heated to the ignition temperature.
- OSTI ID:
- 186789
- Journal Information:
- Scripta Materialia, Vol. 34, Issue 2; Other Information: PBD: 15 Jan 1996
- Country of Publication:
- United States
- Language:
- English
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