CORUNDUM POWDER PRODUCTION BY THE SELF PROPAGATING HIGH-TEMPERATURE SYNTHESIS METHOD

Abstract

The  phase composition, the  crystal size  development in powders, and  microstructure are  investigated in the  article, the  data are  generalized on specific surface and  on corundum powder particle’s size  distribution, the  particles being obtained out  of  solutions by  the  self  propagating high-temperature  synthesis method (SHS)  depending on the  molecular ratio oxidized-to-fuel. It was discovered that the  crystallization rate of   -Al₂O₃-phase decreases and  the crystal size  of this  phase in the  powder diminish with  the fuel  quantity increasing till  the  ratio 1:1:2.  The microstructure is described by larger particles and smaller porous. It is shown that at the ratio 1:1:1,5 the powder specific surface decreases and the powder particles with a size of 20–400   m are  formed. The addition of thiourea at the ratio1:1:2 didn’t  stimulate the  burning. At the  ratio 1:1:1,5 a larger isolated yield of the  corundum powder is obtained than at the  ratio 1:1:2.  Ill. 8. Ref. 15. Tab. 7.