Development of a new graded-porosity FeAl alloy by elemental reactive synthesis

A new graded-porosity FeAl alloy can be fabricated through Fe and Al elemental reactive synthesis. FeAl alloy with large connecting open pores and permeability were used as porous supports. The coating was obtained by spraying slurries consisting of mixtures of Fe powder and Al powder with 3-5 mu m diameter onto porous FeAl support and then sintered at 1100 degrees C. The performances of the coating were compared in terms of thickness, pore diameter and permeability. With an increase in the coating thickness up to 200 mu m, the changes of maximum pore size decreased from 23.6 mu m to 5.9 mu m and the permeability decreased from 184.2 m(3) m(-2) kPa(-1) h(-1) to 76.2 m(3) m(-2) kPa(-1) h(-1), respectively, for a sintering temperature equal to 1100 degrees C. The composite membranes have potential application for excellent filters in severe environments