Fabrication and Composition Investigation of WSi2/MoSi2 Composite Powders Obtained by a Self-Propagating High-Temperature Synthesis Method

In this paper, MoSi2/WSi2 composite powders with different phase compositions were fabricated via a self-propagating high-temperature synthesis (SHS) method. The influence of initial raw material compositions on the formation and the phase evolution of the MoSi2/WSi2 composite powders were investigated. Thermodynamic analysis indicated that the incorporation of W in the starting materials decreased the adiabatic temperature during the SHS reaction, and self-sustainable reaction can be hindered when the W content reached up to 40%. For samples with raw material composition of (\(1-x){\rm Mo}{\cdot} {\rm xW}{\cdot} {\rm 2Si}\) (X = 0.10, 0.20, 0.30, 0.40), composite MoSi2/WSi2 powders can be prepared, which were confirmed by the existence of two fitted peaks that can be assigned to tetragonal MoSi2 (103) and WSi2 (103) crystallographic planes in the XRD fine scan patterns. SEM images also confirmed the existence of two maxima in particle size distributions for samples with high W addition contents. The formation of MoSi2/WSi2 composite powders and the evolution of composite phases reported in this paper may provide an effective strategy for the synthesis of silicide based composite materials.