Mechanical activation of aluminothermic reduction of NiO by high energy ball milling

The effect of mechanical activation on NiO-Al reaction has been investigated by carrying out high energy ball milling using toluene as the process controlling agent NiO reduction reaction progresses gradually and a maximum of 70% reduction has been observed in 20 h of milling. Amorphous alumina forms as the product of NiO reduction and it transforms to stable alpha-Al(2)O(3) at 1000 degrees C via the formation of metastable transition gamma-Al(2)O(3) The activation energy of NiO reduction in unmilled powder is 277 kJ/mol whereas in 20 h milled powder the activation energy has been reduced to 150 kJ/mol. (c) 2010 Elsevier B V. All rights reserved