Effect of material characteristics on the ignition of the combustion reactions induced by ball milling

Raman spectroscopy sheds new light on TiC formation during the controlled milling of titanium and carbon

“…Such a two stem mechanism involving nucleation during earlier stages of milling and rapid exothermal growth at some latter stage is contrary to the existing understanding of MSR, which is based on studies that have used only XRD analysis to characterise as-milled powders [1,[6][7][8][9][10]16]. In these studies, no reaction product was detected prior to t ig , and the heat generated at t ig was thought to be entirely due to the exothermic reaction to form the new reaction product.…”

“…This type of abrupt exothermic reaction taking place during milling has been referred to as a mechanically induced self-propagating reaction (MSR) [7]. Previous studies of mechanically induced self-propagating reactions have described the milling period before t ig as simply an incubation or activation period [1,[6][7][8][9][10]16]. Milling during this incubation period results in reductions in particle and crystallite sizes and intimate mixing of the reactants, which results in an increase in the reaction interfacial area, combined with an accumulation of defects in the powder particles; all of which is thought to result in a reduction in the activation barrier for the reaction.…”

Raman spectroscopy as a tool to study TiC formation during controlled ball milling

“…17 Previous studies of mechanically induced selfpropagating reactions have described the milling period before t ig as simply an incubation or activation period. 4,8,9,[17][18][19][20] Milling during this incubation period results in reductions in particle and crystallite sizes and intimate mixing of the reactants, which results in an increase in the reaction interfacial area, combined with an accumulation of defects in the powder particles, all of which is thought to result in a reduction in the activation barrier for the reaction. It is thought that no reaction takes place until t ig , when ignition occurs, and the reaction then continues as a self-propagating reaction.…”

“…This is contrary to the existing understanding of MSR, which is based on studies that have used only XRD analysis to characterize as-milled powders. 4,8,9,[17][18][19][20] In these studies, no reaction product was detected prior to t ig , and the heat generated at t ig was thought to be entirely due to the exothermic reaction to form the new reaction product. Further work is required to determine whether the formation of reaction product prior to t ig is unique to this system, or if it occurs during milling in other systems where MSR occurs but has simply gone undetected.…”

Nanocrystalline TiO2 by three different synthetic approaches: A comparison

“…El-Eskandarany (1995) showed that there is no remarkable change till 43 ks (~12 h) of milling and the rate of reaction is found to increase with milling time beyond 43 ks and MSSR reaction is found to have come to an end by 360 ks (~101 h) of milling. In our investigations, the MSSR reaction of CuO with metallic Ti is studied by using planetary ball mill without using any process control agent (PCA) like toluene since it is understood that material characteristics affects ignition of the com-*Author for correspondence (anu_guhan@yahoo.co.in) bustion reactions by ball milling (Mingliang et al 2001) like cupric oxide (CuO) system which showed shorter incubation periods than cuprous oxide (Cu 2 O) which required longer milling time (Mulas et al 2001).…”