Microstructure of reduced magnetite as a function of aluminum content and reduction temperature

Samples of porous iron, made from reduction of alumina promoted magnetite (Fe3-xAlxO4), have been studied to investigate how reduction temperature and alumina content affect the pore structure of the resulting iron. There is a systematic change in structure of the porous iron with alumina concentration in the original magnetite phase and with reduction temperature. By choosing suitable values of alumina content and reduction 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 content is attributed to epitaxy and the change in lattice parameter of the magnetite phase. (C) 1997 Elsevier Science B.V.