Spark plasma synthesis and tribological behaviour of Ti-Ni-TiCN nanocomposite

The conventional method of producing titanium components introduces defects into the matrix of the materials, thus resulting in poor microstructure, tribological properties and performance of the materials in service. To overcome these challenges, a Ti-Ni-TiCN nanocomposite was developed using the novel spark plasma sintering (SPS) technique. The morphology and the phases present in the initial powders and the sintered specimen were investigated using the scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. The dry sliding wear behaviour of the sintered samples was studied at ambient temperature by ball-on-disc tests, under an applied normal load of 25 N. The presence of unreacted TiCN, in-situ formed TiN and Ti₂Ni intermetallic phases were revealed by the SEM/EDS analysis and confirmed by the XRD results. The developed titanium matrix nanocomposite displayed a much lower coefficient of friction and wear resistance than the CP-Ti. The strong interface between the matrix and the reinforcements prevents the reinforcements from pulling out of the matrix. Ti-Ni- TiCN nanocomposite showed the predominance of abrasive wear while mixed wear mode was observed, in the CP-Ti. The developed material has the capacity to replace CP-Ti and perform admirably in a tribo-system.