Microstructural configuration and compressive deformation behavior of a TiAl composite reinforced by Mn and in situ Ti2AlC particles

TiAl-5wt.%Ti2AlC-3wt.%Mn composites reinforced by the addition of Mn and in situ synthesized Ti2AlC nanoparticles with a novel microstructure were fabricated. The microstructure and compressive properties of the fabricated composites were thoroughly investigated. The interface between the nanoparticles and the TiAl matrix maintained a very small mismatch and exhibited a stable combination, leading to noticeable grain refinement in the fabricated composites. Furthermore, the yield strength, maximum compressive strength, fracture strain, and strength-ductility balance of the TiAl-5wt.%Ti2AlC-3wt.%Mn composites increased by 30.7%, 10.1%, 5.5%, and 9.9%, respectively, compared with those of the TiAl alloy. The mechanisms by which the properties of the composites were improved mainly thermal mismatch strengthening, Orowan strengthening, grain refinement strengthening, and solid solution strengthening. •In-situ Ti2AlC particles and Mn evolved TiAl alloy into a refined microstructure.•The interface between the TiAl matrix and nanoparticles exhibited a stable combination.•Toughness and strength of TiAl composites were significantly elevated by 9.9% and 30.7%.•The dominant ones were the thermal mismatch and the Orowan strengthening mechanism.