REACTION SINTERING OF ALUMINA-ALUMINIDE ALLOYS (3A)

A novel pressureless reaction sintering process is presented for the f abrication of Al2O3-aluminide alloys (3A). Compacts of intensively mil led metal oxide-aluminum mixtures are heat-treated in Vacuum or inert atmosphere such that the exothermic reactions take place in a controle d manner essentially at temperatures below the melting point of Al. De nse, homogeneous microstructures were obtained with a variety of Al2O3 -matrix systems with interpenetrating networks of aluminides of Ti, Fe , Nb, Mo, Zr, Ni, etc. By adding modifiers in the form of oxides or me tals, volume and phase composition as well as properties can be tailor ed in a wide range.