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A method to simultaneously synthesize and consolidate the silicide WSi: and the composite WSi2-20 vol.%Nb from W, Si, and Nb powders was investigated. Combustion synthesis was carried out under the combined effect of an electric field and mechanical pressure. The fmat density of the products increased nearly linearly with the applied pressure. Highly dense WSi2 and WSi:-20 vol.%Nb with relative densities of up to 97% were produced under the simultaneous application of a 60 MPa pressure and a 3000A current on the reactant powders. The percentages of the total shrinkage occurring before and during the synthesis reaction were 17 and 83% for the WSi2, and 22 and 78% for the WSi:-20 vol.% Nb. The respective Vickers microhardness values for these materials were 8.2 and 5.8 GPa. From indentation crack measurements, the fracture toughness values for WSi2 and WSi2-20 vol.%Nb were calculated to be 3.2 and 9.1 MPa m ~, respectively.

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A method to simultaneously synthesize and consolidate MoSi2-20vol.%Nb composite and MoSi2-20vol.% ZrO2 composite from powders of Mo, Si, Nb and ZrO2 was investigated. Combustion synthesis was carded out under combined electric field and mechanical pressure. Highly dense MoSiz-20vol.%Nb and MoSi2-20vol.%ZrO2 composites up to 96% of theoretical density were produced from powders of Mo, Si, Nb and ZrO2 with 60MPa of pressure and 3000A of current on the reactant.