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.