Molten salt-assisted combustion synthesis and characterization of MoSi2 and MoSi2-Si3N4 composite powders

Abstract

Abstract The possibilities of the synthesis of submicron MoSi2 and MoSi2–Si3N4 composite powders were investigated using inorganic salt-assisted combustion synthesis method. Combustion laws in the MoO3–3Mg–2Si–NaCl and Mo–5Si–NaCl–Si3N4–N2 systems were studied. The main factors influencing the combustion parameters, phase composition and microstructure of products for both these systems were determined experimentally. Optimum synthesis conditions of submicron MoSi2 and MoSi2–Si3N4 composite powders containing 30–40 wt.% of molybdenum disilicide were determined. Compacting conditions for 30 wt.% MoSi2–70 wt.% Si3N4 composite using the hot pressing technique were found. Compact samples 20 mm in diameter were obtained. Microstructure, phase and chemical compositions of the dense samples were studied.