THE APPLICATION OF SELF-PROPAGATING HIGH TEMPERATURE SYNTHESIS TO DRY POWDER MIXTURES: THE METAL AND OXIDIZER POWDERS

Abstract

The results are given  in the article on the growth and progress of α-al₂o₃   crystal phase, that are the crystal sizes,   crystallization degree,  microstructure,  powder specific surface and the particle size distribution, which have  been obtained in course of the burning in the dry mixture of aluminum powder and various kind oxidizers' powders. The aluminum powder burning in presence of oxidizers which were represented by various substances from potassium nitrate to potassium perchlorate works towards the forming of the wider and  at the same time more intensive difraction maximums of α-Al₂O₃   phase. This  results both in  smaller crystalline's sizes  and  in the crystallization degree of the corundum phase. The powder's microstructure's progress is  defined by  the dense sintered particles composed of the softer and harder agglomerations, the microstructure being comparatively porous when  burning in  presence of strong oxidizers. This leads to the less developed powder's specific surface and to the wider particle size distribution, shifted to more coarse fraction 5‒54  microns, unlike  with the powder, obtained  with the  using of  potassium nitrate  which particle size  distribution locates at 0,5001,2 micron. Ill.4. Ref. 15. Tab. 3.