Synthesis and Characterization of Nanocrystalline MoSi2 by Mechanical Alloying and Heat Treating

In order to synthesize nanocrystalline MoSi2, pure molybdenum and silicone powders were milled using an attritor mill with the molar ratio of Mo:Si being equal to 1:2. Mechanically alloyed (MAed) powders were heated in an atmosphere controlled furnace at various temperatures and holding times. The nanopowder characteristics were evaluated by field emission scanning electron microscopy, X-ray diffraction technique, and differential thermal analysis. The obtained results were compared for all prepared samples. The results did not confirm the presence of any related intermetallics after MA. However, Mo5Si3 was formed during heating at 900 A degrees C. An increase in temperature caused the enhancement of the volume fraction of Mo5Si3 and formation of MoSi2. Further heating at 1,100 A degrees C caused the enhancement of the volume fraction of MoSi2, while that of Mo5Si3 was decreased, as during heating at 1,100 A degrees C for 7 h the volume fraction of Mo5Si3 was negligible.