Investigation on the in-situ reaction mechanism of Ti2AlC/TiAl composite prepared by spark plasma sintering

Ti 2 AlC/TiAl composite has shown great potential for the lightweight high-temperature structural materials applied in the new generation of aerospace engines. Understanding the in-situ reaction mechanism of Ti 2 AlC/TiAl composite has been a long-standing challenge with great scientific and practical importance. In this work, Ti 2 AlC/TiAl composites were fabricated via spark plasma sintering at different temperature using Ti powders, Al powders and graphene nanosheets as raw materials. The state-of-the-art analytical tools were employed to give an in-depth investigation on the in-situ reaction mechanism of Ti 2 AlC/TiAl composite. It is innovatively found that the Ti 2 AlC is initially formed by the direct reaction between TiAl and TiC, and the growth of Ti 2 AlC is governed by a Ti 2 AlC prismatic plane-to-TiAl plane incoherent interface, which could provide atomic diffusion channel and promote the reaction between TiAl and TiC. These results could provide the theoretical guideline for the material design and performance optimization of Ti 2 AlC/TiAl composite. • The microstructural evolution of Ti 2 AlC/TiAl composite during SPS was revealed. • The in-situ reaction mechanism of Ti 2 AlC phase was accurately summarized. • The Ti 2 AlC phase was initially formed by the reaction between TiC and TiAl. • The growth of Ti 2 AlC is governed by a Ti 2 AlC/TiAl incoherent interface.