Synthesis and characterization of TiN nanoceramic reinforced Ti-7Al-1Mo composite produced by spark plasma sintering

Materials made from alloys of titanium are of utmost importance for various engineering applications owing to their low density and remarkable mechanical properties. Nevertheless, there is a need to enhance their mechanical properties to improve their capacity for load-bearing applications. In this work, spark plasma sintering technique was employed to fabricate TiN nanoceramic reinforced Ti-7Al-1Mo composite. The influence of nanoTiN reinforcement additions on the densification, microstructural evolution, and mechanical properties of Ti-7Al-1Mo ternary alloy was investigated. Scanning electron microscope equipped with energy dispersive x-ray spectrometer was used to investigate the microstructural evolution. The phases present in the sintered composite were investigated using X-ray diffractometer. Unreinforced Ti-7Al-1Mo alloy showed a microstructure with distinct grain boundaries made up of Widmanstatten lath-like morphology with mainly alpha (alpha) phase and a small percentage of beta (beta) phase. Nano-TiN reinforced Ti-7Al-1Mo composites' morphology revealed a bimodal structure. Ti-7Al-1Mo/7TiN composite was found to possess the highest hardness value of 549 +/- 22 HV1.0 and the highest compressive yield strength of 1295 +/- 7 MPa, which depicts an increment of 74 HV and 323 MPa respectively when compared to unreinforced Ti-7Al-1Mo ternary alloy. The developed composites showed strong potentials for load-bearing applications.