MICROSTRUCTURE OF REDUCED MAGNETITE AS A FUNCTION OF ALUMINUM CONTENTAND REDUCTION TEMPERATURE

Samples of porous iron, made from reduction of alumina promoted magnet ite (Fe3-xAlxO4), have been studied to investigate how reduction tempe rature and alumina content affect the pore structure of the resulting iron. There is a systematic change in structure of the porous iron wit h alumina concentration in the original magnetite phase and with reduc tion temperature. By choosing suitable values of alumina content and r eduction temperature, one may obtain porous iron with any of the three dominant pore structures, each having characteristic orientations of the iron crystallites. The variations in pore structure with alumina c ontent is attributed to epitaxy and the change in lattice parameter of the magnetite phase. (C) 1997 Elsevier Science B.V.