Role of Nano-TiC particles in enhancing the microstructure and wear resistance of IN718 superalloys fabricated by directed energy deposition

In this study, TiC-reinforced IN718 composites containing various fractions of TiC nanoparticles are fabricated using directed energy deposition. The microstructure, elemental segregation, hardness response, and wear performance of the composites are systematically investigated. First-principles calculations confirmed the segregation behavior of Nb and Mo atoms, revealing that their incorporation enhances the interfacial bonding strength and structural stability at the TiC (001)/NiCrFe (001) interface. Compared with the IN718 superalloy, the 10 wt% TiC/IN718 composite exhibites a reduced crystallographic texture and an increase in hardness of 17.3 %, as well as the most stable wear behavior. In the 20 wt% TiC/IN718 composite, the TiC particles resolidify into dendritic morphologies, improving wear resistance by 45.1 %. Overall, the wear resistance of the composites improves with increasing TiC content, whereas wear stability is closely correlated with the hardness.