Porous FeAl alloys via powder sintering: Phase transformation, microstructure and aqueous corrosion behavior

This study investigates the phase transformation and microstructure of porous FeAl parts sintered from elemental powder mixtures using in-situ neutron diffraction and in-situ thermal dilatometry. A single B2 structured FeAl phase was determined in the sintered FeAl alloy. The combined effects of the Kirkendall porosity, transient liquid phase, and phase transformations associated with powder sintering all contribute to the swelling phenomenon of the final sintered part. The aqueous corrosion test indicates that the corrosion products include iron oxides in the porous FeAl parts. The accumulation of corrosion products blocks the pore channel and decreases pore size and permeability over the soaking time.