Novel processing of intermetallic matrix composites using in situ displacement reactions

The utilization of in-situ displacement reactions is being investigated as a means of producing in-situ dispersoids and tailored interfaces in intermetallic matrix composites. The systems under investigation include MoSi2 and NiAl matrices containing ceramic (e.g., SiC and Al2O3) and/or refractory metal (e.g., Mo and W) reinforcements. Processing schemes include conventional compositing routes, mechanical alloying and diffusion couples for more fundamental studies. The elimination of silica and the production of SiC dispersoids in MoSi2 by mechanical alloying Mo, Si and C powders prior to consolidation is described. In addition, it is shown that it is possible to form refractory metal carbides at the interfaces between NiAl and molybdenum and tungsten by alloying NiAl with carbon