MoSi{sub}2 FORMATION MECHANISMS DURING A SPARK PLASMA SYNTHESIS FROM MECHANICALLY ACTIVATED POWDER MIXTURE

摘要

Dense molybdenum disilicide with a nano-organized microstructure was synthesized by mechanical activation, for producing nanostructured agglomerates of a 1:2 mixture of Mo and Si, followed by the synthesis/consolidation in one step using SPS technology. In order to synthesize a dense molybdenum disilicide with a perfectly controlled microstructure, an investigation of the influence of Spark Plasma Sintering processing parameters (temperature, heating rate, mechanical pressure and holding time) on the chemical composition and the microstructure characteristics has been performed. The present work shows also that the so-obtained materials present better oxidation resistance in comparison to a dense microstructured M0Si{sub}2, due to the silica scale formation under high temperature oxidizing atmosphere. The most interesting results are obtained at "low" temperature (673 - 873K).