Ferroboron combustion

The microstructure of products of ferroboron combustion in nitrogen has various morphological forms. At the same time, a significant difference is visible in shape of particles of external and central parts of the burned sample. The presence of amorphous boron in the original material influences the process of nitride formation because (according to XRD analysis) amorphous boron contains boric acid which decomposes during combustion forming boric anhydride and water. 

Combustion of Ferroboron in Nitrogen and Synthesis of Boron Nitride... 

Figure 7.29 SEM images of original ferroboron particles (a) and products of nitriding with a stopped combustion front (quenched) (b).

Figure 7.30 SEM images of particles of products of ferroboron nitriding with addition of 10% of amorphous boron (a-d) outer part of the combusted sampie.

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