An investigation of the combustion synthesis of MoSi 2β-SiC composites through electric-field activation

Abstract

Using field-activated combustion synthesis (FACS), composites of (1− x) MoSi 2− xSiC were prepared directly from elemental powders. Systems with 0< x≤0.18 can sustain a combustion wave but the product contained unreacted Si and C in addition to MoSi 2 and β-SiC. Systems with x>0.18 do not sustain a wave without the application of an external electric field. Composites of MoSi 2 and β-SiC can be synthesized for 0≤ x≤1.0 in the presence of fields above threshold field values. The threshold value decreased with increasing x value. Both combustion wave velocity and temperature increased nearly linearly with an increase in field above the threshold value for any given composition ( x value). The influence of carbon particle size on the dynamics of the synthesis and the effect of the magnitude of the field on the nature and microstructure of the product were also investigated.