Preparation of Fine Mullite Powder in a SHS Chemical Furnace System

摘要

Within a very short heating period, fine mullite powder with practicle size below 1μm was obtained in a novel synthesis system, a self-propagating high-temperature synthesis (SHS) chemical furnace, from which the tremendous heating derived. The combustion reactants consisting of Ni, Al and TiC were chosen as a chemical furnace in this system to supply the heat, calcining temperature was increased at a heating rate of 1350K/min in the heating process, till the maximum temperature (1350°C). The rapid mullitization process was performed within 1min, microstructure analysis indicated that small mullite grains (＜50nm) were crystallized, fine mullite particles (＜1μm) with narrow particle size distribution, favorable activity for sintering were derived. And significant grain growth was observed in mullite powder, when the combustion reactants consisting of Ni, Al and ＜30mol.% TiC.