Powder Metallurgy Manufacturing of Iron Aluminides with Different Aluminium Contents and Magnesium Addition by Reactive Hot Pressing

Abstract

In this work, iron aluminide materials, which are promising candidates for high temperature applications, are manufactured through reactive hot pressing of elemental powder mixes, facilitating a straightforward preparation of well-densified materials with a high degree of microstructural homogeneity. The impact of varying Al additions on reaction behavior, microstructural and compositional features of the resulting materials is evaluated. Furthermore, the effect of adding 1 wt. % Mg on reactivity and phase formation is illustrated. The results show that reactive hot pressing of elemental powders in the Fe-Al and Fe-Al-Mg systems at 1000 °C results in residual porosities well below 5 %. Magnesium addition significantly increased reactivity between constituents, leading to slightly improved densification without exhibiting potentially detrimental segregation phenomena. The processing approach presented in this work leads to material characteristics which are promising in the context of developing materials with favorable mechanical and tribological performance at elevated temperatures.