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Preparation of nanocrystalline ZrB 2 -based powder by aluminothermic and magnesiothermic reductions in M/ZrO 2 /B 2 O 3 (M = Al or Mg) systems was investigated.In this research, high energy ball milling was employed to persuade necessary conditions for the occurrence of a mechanically induced self-sustaining reaction (MSR).The happening of MSR reactions was recorded by a noticeable pressure rise in the system during milling. Ignition times for ZrB 2 formation by aluminothermic and magnesiothermic reductions were found to be 13 and 6 minutes, respectively. Zirconium diboride formation mechanism in both systems was explained through the analysis of the relevant sub-reactions.

Aluminium and magnesium were used in the M/ZrSiO 4 /B 2 O 3 /C (M=Al, Mg) system to induce a mechanically induced self-sustaining reaction (MSR). Aluminium was not able to reduce the system to the desired products, and the system became amorphous after 10 hours milling. However, Nanocomposite powder of ZrB 2 -SiC-ZrC was in-situ synthesized by the magnesiothermic reduction with an ignition time of approximately 6 minutes. The mechanism for the formation of the product in this system was determined by studying the relevant sub-reactions.

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Nanocrystalline zirconium diboride (ZrB 2 ) powder was produced by magnesiothermic reduction in the Mg/ZrO 2 /B 2 O 3 system. In this study, high-energy ball milling was used to generate the essential conditions to induce a mechanically induced self-sustaining reaction (MSR). The ignition time for ZrB 2 formation was found to be approximately 6 minutes. The mechanism for the formation of ZrB 2 in this system was determined by studying the relevant sub-reactions, the effect of stoichiometry, and the thermal behavior of the system.

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