Papers by Keyword: Mullitisation

Abstract: The effect of active alumina on the sintering behavior of andalusite powder was studied. The results revealed that the addition of active alumina delayed the decomposition of andalusite and primary mullitization, beginning temperature of secondary mullitization was about 1350°C. The temperature at which the effect of expansion of the secondary mullitization emerged was about 1400°C, and the expansion effect of secondary mullitization did not yet complete at 1600°C.

Abstract: 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 1 min, 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 <30 mol.% TiC.