Structure and Compressive Behavior of Fe25Cr5Al Metallic Honeycomb Fabricated by Powder Extrusion Molding and Sintering

Fe25Cr5Al honeycomb has been fabricated by powder extrusion molding and sintering using a mixture of metal powders and additives.The extrusion molding,effects of sintering temperature and time on the macro and micro structure,and compressive behavior of the honeycomb have been studied.The extruded honeycomb′s apparent density was 0.87-0.95 g/cm3 while extrusion pressure and composition of powder mixture were 6-9.5 MPa and 0.625-0.725 respectively.The geometric structure parameters,such as cell number ( in the range) and specific surface area( in the range of 1.95-2.19 mm2/mm3),increased with the increasing of sintering temperature and time.The sintering microstructure consised of α-Fe,Al-Cr and Al-Fe intermetallics,Cr2O3 and Al2O3.The compressive strength varied with the apparent density.In the transverse direction,the compressive deformation involved single cell layer yielding and the compressive strength was in the range of 1.4-6.5 MPa (with apparent density 0.76-0.94 g/cm3),however,in the longitudinal direction,the deformation was related to a mechanism of multi deformation band yielding and the yield strength was in the range of 8.2-15.3 MPa (with apparent density 0.78-0.89 g/cm3).