Effect of graphene nanoplatelets (GNP) content on mechanical properties and wear resistance of in-situ Ti/TiC composites at room and high temperatures

This research investigates the influence of GNP loading on microstructure, mechanical properties and tribological behavior of commercially pure titanium (CP-Ti). Materials were synthesized by spark plasma sintering (SPS) of the milled Ti/GNP powders at 1100 °C. The scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis results confirmed the in-situ formation of TiC particles during sintering. The results showed that with an increase in GNP content, both hardness and yield stress exhibited a continuous rise. Specifically, the hardness increased from 274 HV in CP-Ti to 375 HV in the Ti/3GNP composite, while the compressive yield strength rose from 677 MPa to 1600 MPa. However, the composite containing 0.5 wt% GNP showed the most optimal combination of properties, including an ultimate compressive strength of 1798 MPa, a fracture strain of 41.6%, and the lowest specific wear rate at both 25 °C and 300 °C (5.12 × 10 -13 m 3 /Nm and 1.67 × 10 -13 m 3 /Nm, respectively). This study demonstrates that achieving an optimal balance between hardness and toughness through controlling the formation of the TiC phase is the key to attaining superior wear performance.