The reduction of V2O5 using Mg, Al, and Ti as reductants during mechan
ical milling in a ball mill has been studied. With all three reductant
s, a combustion reaction was observed after milling for a critical ign
ition time. Using Mg as the reductant, the ignition time was found to
increase with decreasing collision energy. However, the combustion eve
nt could not be associated with a critical degree of microstructural r
efinement or a reduction of the ignition temperature. With both Mg and
Al reductants TEM examination of the as-combusted powders showed the
presence of nanoscale single crystal smoke particles, similar to those
formed by gas evaporation techniques. (C) 1994 Academic Press, Inc.