Fabrication of In Situ TiC Reinforced Ti Matrix Composites by Thermomechanical Consolidation of TiH sub(2)/CNTs Powder Mixtures

In this work, in-situ TiC reinforced Ti matrix composites (TMCs) have been fabricated via blending TiH sub(2) powder and multi-walled carbon nanotubes (CNTs) followed by thermomechanical consolidation of the TiH sub(2)/CNTs powder mixture. The dehydrogenation, in situ reaction and consolidation occurred simultaneously and took less than 15 minutes in total. The effect of CNTs content (1 and 3 vol.% (0.56 and 1.69 wt.%)) on the evolution of microstructures and mechanical performances of the extruded samples has been investigated. The results showed that the extruded TMCs had a duplex microstructure consisting of coarse alpha titanium grains and ultrafine grained (UFG) regions, and the in-situ formed TiC particles had a near-spherical shape. The extruded sample with 1 vol.% (0.56 wt.%) CNTs reinforced exhibited a yield strength of 807.3 MPa, ultimate tensile strength of 1085.9 MPa and elongation to fracture of 3.3% at room temperature. The mechanism of microstructural evolution and material failure are discussed.e are discussed.