Structural characterization of combustion synthesized MoSi 2 –Si 3 N 4 composite powders and plasma sprayed MoSi 2 –Si 3 N 4 composites

A systematic structural characterization has been conducted on combustion synthesized MoSi 2 –Si 3 N 4 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 Si 3 N 4 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.