Magnesium aluminate (MgAl2O4) spinel produced via self-heat-sustained (SHS) technique

Usage of a new but simple and reactive technique employing metallic aluminu m as one of the reactants to produce very high phase-purity magnesium alumi nate powder under rather mild experimental conditions is described, Low tem perature melting of aluminum and subsequent exothermic reaction between mol ten aluminum and magnesia appeared to have led to the powder with a very hi gh fraction of the spinel phase with small particle size and narrow particl e size distribution. This powder upon sintering for 4h at 1600 degreesC led to compacts with density as high as -92% with benign microstructural featu res, The beneficial effect of slightly off-stoichiometry (similar to 9wt,%) in compositions on either side of magnesium aluminate in the starting powd ers has been discussed. (C) 2001 Elsevier Science Ltd, All rights reserved.