Yielding, hardening and creep behavior of iron aluminides

Abstract

Engineering properties of powder processed iron aluminides(Fe-24 wt.% Al alloy).obtained by hot extrusion and roll compaction of water atomized powder were investigated to assist in the structural analysis of FeAl components exposed to short-time, thermal-mechanical loadings. The test matrix for high-temperature deformation of FeAl incorporated powder processed sheet and bar product forms. Tensile, cyclic, creep and relaxation tests were carried out from room temperature to 750 οC on the bar products. Sheets were characterized for their tensile and creep properties. The experimental data were sufficient to provide rules for yielding, hardening and creep in the temperatures range of 23–750 οC. The room temperature curve adjusted for the temperature dependence of the modulus may be used for the yield and hardening behavior between 23 and 600 οC. Above 600 οC, the yield can be obtained from the tensile curve for the temperature of interest. Exposure to 750 οC causes sufficient recovery and resets the kinematic and isotropic hardening parameters to their initial values. Variation of Young's modulus with increase of temperature is also presented. Limited creep behavior is also discussed. Structural analysis of the FeAl components can be carried out using finite element modeling techniques with the availability of the tensile, cyclic, relaxation and creep behavior of FeAl at elevated temperatures.