Densification and Structural Evolution in Spark Plasma Sintering Process of Mechanically Alloyed Nanocrystalline Fe-23Al-6C Powder

Abstract

Nanocrystalline Fe-23 at%Al-6 at%C alloy powder was produced by mechanical alloying of the mixture of iron powder and aluminum powder (Fe-25 at%Al) with methanol, and was consolidated into fully dense compact by spark plasma sintering (SPS) at 1273 K. The compacts have nanocrystalline microstructure composed of mixture of α-phase grains and κ-carbide (Fe 3AlC) grains whose average grain size is about 50 nm. Although relatively large grains were also observed in places, their sizes were not over a few micrometers. The mechanisms of the densification and the structural evolution during the SPS process are discussed.