Structural and mechanical characterization of porous iron aluminide FeAl obtained by pressureless Spark Plasma Sintering

In this article, structural and mechanical characterization of porous iron aluminide FeAl with a high open porosity obtained by one-step fast synthesis is presented. FeAl compacts produced by pressureless Spark Plasma Sintering of the Fe-40at%Al powder mixtures at 800 and 900 °C for 3 min had open porosities of 41% and 46%, respectively. An important result of this work is high values of the open porosity of the synthesized FeAl achieved without any pore forming additives by inducing a rapid chemical reaction between iron and aluminum in an electric current-assisted sintering process. Transverse rupture strength (TRS) of the porous FeAl was determined from the experiments on indentation of a steel ball into the disk-shaped sintered specimens. Finite element modeling of the specimen rupture during indentation was carried out in ANSYS 17.0 software. The TRS values of the FeAl compacts obtained analytically were close to those obtained numerically. The TRS of the porous FeAl sintered at 700-900 °C ranged between 53 and 72 MPa and did not change significantly with the sintering temperature.