Fabrication of Inconel 718 composites reinforced with TiCN via laser powder bed fusion: Integration of triply periodic minimal surface lattice structures

The integration of TiCN particles into superalloy composites for laser powder bed fusion (LPBF) and the construction of Triply Periodic Minimal Surface (TPMS) lattice structures have been understudied. This research systematically examines the microstructure and mechanical properties of LPBF-processed 10 vol% micron sized TiCN particle reinforced Inconel 718 (IN718) composites. The compressive behavior of the resultant TPMS lattice structures, derived from the TiCN-IN718 composite, was scrutinized through a combination of experimental testing and Finite Element (FE) simulation. The micro-sized TiCN reinforcement is demonstrated to notably augment the hardness, tensile strength, and wear resistance of the LPBFed TiCN-IN718 composite. Furthermore, the application of homogenization-solution-aging (HSA) heat treatment is shown to provide additional enhancements to the composite's mechanical behavior. Both the TiCN reinforcement and the HSA heat treatment are identified as pivotal factors influencing the compressive response of the TPMS lattice structures. Experimental findings indicate that the HSA-treated D-structure attains the highest compressive strength, reaching 122 MPa, outperforming both the G- and P-structures. During quasi-static compression testing, the D- and G-structures undergo a layer-by-layer collapse, while the P-structure exhibits tilt shear band behavior. The congruence between FE simulation results and experimental data substantiates the simulation's reliability and its capacity to accurately evaluate the mechanical behavior of TPMS lattice structures.