Fabrication and characterization of Ti-TiB2 functionally graded material system

In this work, a five-layer metal-ceramics Ti-TiB₂ functionally graded material (FGM) system was fabricated using a powder metallurgy route. The fabricated FGM system was found to possess 50 pct more fracture toughness than the conventional monolithic TiB₂ ceramics. The composition and microstructure of the FGM fabricated were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX), and the results are presented and discussed in this article. Vickers hardness and fracture energy of each compositional layer in the FGM were also measured. The significant fracture toughness improvement observed in the FGM system is attributed to the operation of a crack deflection mechanism. The present experimental results were compared with the theoretical predictions reported in the literature on operating crack deflection criteria of layered systems.