Fe-Al intermetallic compound is regarded as one of the promising high-temperature structural materials due to low cost, low density, superior oxidation resistance and good corrosion resistance, etc. This kind of material is hopeful to be widely used in the aeronautic, aerospace and high thrust-weight ratio engine industry. However, the engineering application of the Fe-Al intermetallic has been limited by its poor ductility at room temperatures. In addition, its strength and creep resistance decrease above 600 ℃. In order to overcome these shortcomings, many investigations have been carried out, for example, mechanical alloying, micro alloying by adding other trace elements e.g. Zr, Nb and Cr, compounding by adding some continuous or discontinuous reinforced phases, heat treatment, and so on. The directional solidification technique is an attractive method to obtain well aligned microstructure by controlling crystal growth orientation along with the heat flow direction. In the present paper refractory metal Ta was added to Fe-Al intermetallic compound to prepare Fe-Al-Ta eutectic composites by a modified Bridgman directional solidification technique and electron beam floating zone melting technique, respectively. Microstructures of the directionally solidified Fe-Al-Ta eutectic composites are regular eutectic at the low solidification rate, and the eutectic colony is formed at the high solidification rates. The composites are composed of two phases: disordered Fe(Al,Ta) matrix phase, and ordered Fe₂Ta(Al) Laves phase. The solid/liquid interface evolves from planar interface to shallow cellular interface, then to deep cellular, and finally to shallow cellular planar with the increase of the solidification rate. Moreover, the tensile property, the fracture toughness, and fatigue property were evaluated. It is found that the mechanical properties of the Fe-Al-Ta eutectic composites are better than that of the as-cast Fe-Al-Ta eutectic alloy because of the directional heat flow during solidification process. Finally, the fracture morphologies of the Fe-Al-Ta eutectic were observed and the strengthening mechanism of Fe-Al-Ta eutectic was discussed. 

Chunjuan Cui obtained her M.E. degree and Ph.D. degree in Materials Processing Engineering from Northwestern Polytechnical University and served in school of Metallurgical Engineering, Xi’an University of Architecture and Technology now. She is currently a professor and doctoral supervisor. She performed collaborative research from Feb.2013 to Feb.2014 in University of Kentucky, USA. She has published more than 50 journal papers, and more than 30 of them were indexed by SCI and EI. She also published an academic monograph on metal solidification theory and application technology. Her team’s research interests are theory and technology of directionally solidified metal matrix composites.