Bimodal laminated Ti₃Al matrix composite achieved by in situ formed Ti₅Si₃ reinforcements

The low density and high-temperature mechanical properties of intermetallic Ti₃Al based alloys are highly desirable for a wide range of critical applications. In this paper, we designed and prepared a novel laminated Ti₅Si₃/Ti₃Al composite (LTTC) consisting of alternating Ti₅Si₃-lean/coarse-grained Ti₃Al layers (TCLs) and Ti₅Si₃-rich/fine-grained Ti₃Al layers (TFLs). The processing route involves hot pressing of a stack of alternating Ti foils and Al-6Si foils, followed by a two-step reaction annealing. The tensile properties of the LTTC have also been evaluated, and the LTTC exhibited a good strength-ductility combination when compared with monolithic Ti₃Al. By in-depth mechanism discussion, we propose the possible approaches to further enhance the mechanical properties of such LTTC.