Deformační chování aluminidu železa typu Fe40Al-Zr-B za tepla

Abstract

The presented dissertation thesis deals with the study of deformation behaviour and structure-forming processes of selected alloys based on Fe-40at.% Al, i.e. iron aluminides with extremely low hot formability. For experimental purposes primarily the Fe-40Al-Zr-B alloy was chosen. The main attention was paid to hot forming and relevant structure-forming processes taking place in the alloy Fe-40Al-Zr-B. The main part of the experimental work was performed on the plastometer GLEEBLE 3800. The activation energy of Fe-40Al- Zr-B alloy during hot forming was calculated on the basis of the results of plastometric tests performed at temperatures from 800 ° C to 1200 ° C and at the strain rate values from 0.05 s -1 to 30 s -1. This value was used to build the mathematical models describing the maximum deformation resistance and kinetics of dynamic recrystallization of the alloy during hot forming. Relaxation tests of the alloy of Fe-40Al-Zr-B of the initial cast structure (i.e. very heterogeneous and coarse-grained) were performed also on the plastometer GLEEBLE 3800. The aim was to cause static recrystallization and achieve the uniform grain size. On the basis of the patent process of hot forming of the Fe-40Al-Zr-B alloy it was possible to optimize the parameters of forming of iron aluminide, which is practically impossible without the protective capsule.