On the Synthesis Mechanism of TiN, ZrN, and HfN During Combustion of Mixtures of Aluminum Nanopowder with TiO2, ZrO2, and HfO2

Resumo

The technology for synthesizing TiN, ZrN, and HfN involves combustion in air of mixtures of aluminum nanopowder (NPAl) and the corresponding dioxides and contradicts thermodynamic calculations. Nitrides should be oxidized in the presence of air and converted to the oxides. The synthesis of nitrides in air is a new direction in the technology of refractory nitrides. Nitrogen from air is used in the proposed technology. The synthesis occurs at atmospheric pressure with free access of air. Complicated equipment is not required. Energy consumption is minimal. The synthesis proceeds spontaneously (exo-effect) after initiation. Mixtures of NPAl and the dioxides are reduced to the metals (Ti, Zr, Hf) or suboxides during combustion in air. Subsequent nitriding proceeds if the oxygen chemical activity is diminished.