Fabrication of in situ Ti5Si3/TiAl composites with controlled quasi-network architecture using reactive infiltration

Fully dense Ti5Si3/TiAl composites were successfully in situ synthesized by reactive infiltration using Ti powders and Al-Si alloys as raw materials. Fine Ti5Si3 particles exhibit a unique quasi-network distribution, remarkably hindering the coarsening of α2/γ lamellar colonies. Compared to the as-cast samples, the mean size of lamellar colonies is much finer and thus the resulting Ti5Si3/TiAl composites show the enhanced room temperature elongation, up to 2.5%, while retaining the ultimate tensile strength of 414 MPa. Moreover, Ti5Si3/TiAl composites display superior high temperature tensile properties. Consequently, the novel Ti5Si3/TiAl composites have potential for high temperature applications in aeronautics and aerospace.