Fabrication, microstructure and mechanical properties of TiAl matrix composite reinforced by submicro/nano-Ti2AlC

In the present work, using pre-alloyed Ti-48Al-2Cr-2Nb powders and graphene nanosheets as raw materials, the TiAl matrix composite reinforced by submicro/nano-Ti2AlC was fabricated via spark plasma sintering and subsequent heat-treatment. The microstructure characterization results have indicated that submicro-Ti2AlC and nano-Ti2AlC exhibit the coherent atomic correspondence with the full lamellar TiAl matrix. Furthermore, The Ti2AlC/TiAl composite has excellent balance relationship of room-temperature compression strength (-2171 & PLUSMN; 3 MPa) and fracture strain (-31 & PLUSMN; 1%). The submicro-Ti2AlC could effectively hinder the twin propagation and inhibit the dislocations motion, which is benefit to improve the strength of the Ti2AlC/TiAl composite. In addition, the nano-Ti2AlC could not only cause the dislocation multiplication in & gamma;-TiAl by the activation of pyramidal dislocations, but also induce the formation of deformation twins in & gamma;-TiAl by the basal-plane slip, resulting in the improvement of plastic deformation capacity in the Ti2AlC/TiAl composite.

Automated summary

In this study, a TiAl matrix composite reinforced by submicro/nano-Ti2AlC was fabricated using pre-alloyed Ti-48Al-2Cr-2Nb powders and graphene nanosheets as raw materials via spark plasma sintering and subsequent heat-treatment. The microstructure characterization results showed that the submicro-Ti2AlC and nano-Ti2AlC had coherent atomic correspondence with the full lamellar TiAl matrix. Furthermore, the Ti2AlC/TiAl composite exhibited an excellent balance relationship between room-temperature compression strength (-2171 ± 3 MPa) and fracture strain (-31 ± 1%).