Synthesis and mechanical properties of TiC<inf>x</inf> and Ti(C,N)reinforced Titanium matrix in situ composites by reactive spark plasma sintering

In this study, Ti powders were ball-milled with 2 wt% graphene nanoplatelets (GnP)and graphitic carbon nitride (g-C3N4)and subjected to spark plasma sintering (SPS)in order to prepare Ti-TiCx and Ti–Ti(C,N)composites. Dispersion of GnP and g-C3N4 in Ti matrix after milling was analysed. The effect of GnP and g-C3N4 on microstructure, phase evolution and the mechanical properties of the resultant composites were studied. Lattice parameter evaluation indicated the presence of TiC0.40 phase in the sintered compact of Ti-2GnP whereas Ti(C, N)was found to be formed in Ti-2g-C3N4 compact. Microstructural studies indicated finer secondary phase in Ti-2g-C3N4 compared to Ti-2GnP due to well dispersion of g-C3N4 in Ti during milling. Ti-2g-C3N4 showed superior Vickers hardness (820 ± 28 VHN), elastic modulus (168 GPa), nanohardness (12 GPa), room temperature (2.9 GPa)and high temperature compression strength (120 MPa)compared to other composites and pure Ti.