Effect of fabrication methods on microstructure and mechanical properties of Fe 3Al-based alloys

Abstract

Disordered Fe(Al) solid solution powders with nano-grain size were fabricated by mechanical alloying, and subsequently the milled powders were consolidated by plasma activated sintering (PAS) and hot pressing (HP), respectively. The effect of the two fabrication methods on microstructure and mechanical properties of Fe 3Al was investigated. Disordered Fe 3Al with submicron-grain size was obtained by PAS, while ordered Fe 3Al with micron-grain size was obtained by HP. Compared with ordered Fe 3Al with micron-grain size by HP, disordered Fe 3Al with submicron-grain size by PAS had higher hardness and toughness. Fe 3AlC 0.5 was precipitated in all specimens with methanol addition during mechanic alloying. The precipitation of Fe 3AlC 0.5 improved the hardness of Fe 3Al, but was harmful to the toughness of Fe 3Al.