Microstructure and wear properties of laser-deposited functionally graded Inconel 690 reinforced with TiC

Functionally gradient material (FGM) can be tailored to the structural requirements of the final product. In this study, titanium carbide (TiC) reinforcement particles were embedded in Inconel 690 with laser direct deposition to build functionally gradient metal matrix composites (FGMMCs). The microstructures of the MMC and distribution of TiC particles were characterized with an optical microscope, SEM and X-ray diffraction. There was a near absence of internal voids in the deposited TiC-Inconel 690 MMC. With the volume percentage of TiC particles in the depositions varied from 0 to 49%, a drastic evolution in the microstructure was observed and the presence of TiC particles over 30% yielded a refinement of the matrix microstructure and introduction of a finely dispersed crystalline phase. High-temperature dissolution of TiC was not detected under the conditions used. Micro-hardness and wear resistance tests showed a significant improvement with increased TiC content.