Powder processing of FeAl sheets by roll compaction

Powder metallurgical processing techniques were employed to manufacture 0.2 mm thickness of iron aluminide sheets based on Fe-40 at% Al using water atomized powder of an FeAl alloy containing C, B, Mo and Zr as alloying elements. Powders of FeAl mixed with polymeric binders were roll compacted using two counter rotating rolls to a thickness of approximately 0.66 mm. Roll compacted sheets were then debindered in nitrogen using a two stage debindering cycle over a period of several hours to effectively decompose the binder. Debindered sheets were vacuum sintered prior to cold rolling them for densification in several different stages. The properties of the FeAl sheets are dependent on the processing temperature, Al content of the final sheet, oxygen content, and the microstructure. Sheets exhibit fine microstructure with a dispersion of Al2O3 particles throughout the matrix. Variation of electrical resistivity, specific heat, thermal expansion, and thermal diffusivity with variation of temperature is presented, and compared with 304 steel.