Structural characterization of combustion synthesized MoSi2–Si3N4 composite powders and plasma sprayed MoSi2–Si3N4 composites

A systematic structural characterization has been conducted on combustion synthesized MoSi2–Si3N4 powders and plasma sprayed composites by transmission electron microscopy (TEM). The powders are cleaner and with little surface oxide contamination than most commercial powders. The distribution of the two phases can be tailored by modifying the synthesis conditions, which has resulted in improved retention of Si3N4 after plasma spraying. TEM studies performed on deformed composites indicate a strong link between even dispersion of second phases and enhanced dislocation plasticity in the plasma sprayed composites.