Effect of TiC Particle Size on Processing, Microstructure and Mechanical Properties of an Inconel 718/TiC Composite Material Made by Binder Jetting Additive Manufacturing

In this paper, the effect of TiC particle size on the microstructure and mechanical properties of an Inconel 718/TiC composite material fabricated using binder jetting additive manufacturing was investigated. Vacuum sintering, hot isostatic pressing and heat treatment as post-processing were applied to the samples. The addition of 1 wt% micron-sized TiC to the Inconel 718 matrix resulted in a significant increase in strength and relative elongation during tensile tests at both room temperature and 700 °C. The distribution of micron-sized TiC particles in the matrix was uniform, and the MC phase precipitated after HT was located along the grain boundaries and near the micron-sized TiC particles, which contributed to the strengthening. The hardness increased insignificantly with the addition of micron-sized TiC. The nano-sized TiC particles added to the matrix were located on the surfaces of the Inconel 718 particles of the initial powders, which obstructed sintering and resulted in a porous structure and, consequently, low mechanical properties.