Microstructure and Mechanical Properties of FeAl Intermetallics Prepared by Mechanical Alloying and Hot-Pressing

FeAl intermetallics were prepared by mechanical alloying and vacuum hot-pressing. The Fe-48 at.% Al powder was ball-milled for 3-12 h, producing a solid solution structure of Fe (Al) with trace Al (Fe). Subsequent vacuum annealing or hot-pressing introduced phase transformations into the FeAl (B₂) intermetallics and Al₂O₃ inclusions. The hot-pressed FeAl intermetallics possess a high flexural strength of 831 MPa and a fairly good strain at break of 3.2%. The results show that the addition of 0.5 at.% B reduces the peak temperature for hot-pressing from 1180℃ to 1100℃, and increases the density of the compacts from 95% to 96.3%, but results in no significant improvement in the mechanical properties.