The kinetics of non-isothermal iron and aluminum powder mixtures sintering in protective atmosphere

In this paper, the analysis of non-isothermal reaction kinetics of pure elemental Fe and Al powders sintered in argon atmosphere is presented. The attention was drawn to the numerical methods which increase the accuracy of kinetic and thermodynamical parameters evaluation such as activation energy, enthalpy of formation and Avrami power factor. The verification of proposed phase transformation model associated with sintering process of elemental Fe and Al powders is also presented. DSC, XRD and SEM techniques showing the relationship between the phenomena of phase transformations in FeAl intermetallic alloy are applied. The results of determination of activation energy, enthalpy of formation and Avrami power factor for phase transformations occurring during the process, based on JMA kinetic model, Kissinger equation and stoichiometric calculations assumed a sequence of changes are presented. Moreover, the hypothetical model of intermetallic phase synthesis and transformation in elemental component is presented.

► All Al-rich phases from Fe–Al equilibrium system in tested sinters were observed.
► Fe–Al phases formation can be described by JMA model aided by Rietveld analysis.
► The compacting pressure has a crucial influence on the sintering kinetics.