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Model of static recrystallization in the coarse-grained B2 iron aluminide
Schindler, I. ; Šumšal, V. ; Kopeček, Jaromír ; Kawulok, P. ; Jozwik, P. ; Rusz, S. ; Kawulok, R. ; Opěla, P.
Microstructure of the laboratory castings made from Fe-40at.%Al-Zr-B alloy was homogenized by the multipass hot rolling in protective capsules and subsequent lannealing. Based on the isothermal hot compression tests and EBSD analysis, the sufficiently accurate model describing the static recrystalization kinetics of the such prepared coarse-grained B2 iron aluminide after strain 0.2 was developed. The independent variables in this model are temperature of deformation as well as annealing time equal to the deformation temperature. Unexpected effect of the previous strain value on the static softening was observed. Static recrystallization begins relatively easy in the studied alloy in the whole range of testing temperatures (900-1100 °C), but a very long-term annealing is quite necessary for the complete course of recrystallization.\n
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Effect of chemical composition on the hot deformation behavior of selected iron aluminides
Šumšal, V. ; Schindler, I. ; Kopeček, Jaromír ; Šíma, V.
The influence of chemical composition on the deformation resistance of iron aluminides was studied by the plastometric tests on three types of Fe – 40 at. % Al based materialsalloys; especially the influence of zirconium and boron, respectively effect of fine TiB2 particles addition was investigated. All materials were prepared using the identical procedure. The samples were pre-heated to a temperature of 1200 °C and then deformed at temperatures from 800 to 1200 °C, the nominal strain rate was 0.05 s-1, 0.4 s-1-1, 4 s-1 and 30 s-1. The relationship describing the maximum deformation resistance of aluminides depending on the temperature-compensated strain rate was derived from obtained data. The values of activation energy and hot deformation resistance of the studied materials were compared and the differences interpreted in terms of physical-metallurgical effects of additives.
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