Synthesis and characterization of spark plasma sintered FeAl and in situ FeAl-Al<inf>2</inf>O<inf>3</inf> composite

In the present work, nanocrystalline FeAl and FeAl-Al2O 3 composite were synthesized by high energy ball milling and subsequent compaction by spark plasma sintering. Microstructural changes during all stages of processing are studied using X-ray analysis. After 20 h of milling, the disordered FeAl and some amount of Fe rich solid solution was obtained in both of these compositions. Subsequent heat treatment results in formation of ordered FeAl. However, disordering of FeAl was observed in both compositions after spark plasma sintering. Nanocrystallinity is retained in both the compositions even after sintering at high temperature of 1,000 C. Very high hardness of ~575 HV1 and ~600 HV1 was exhibited by FeAl and FeAl-Al2O3 composite. © 2013 Indian Institute of Metals.