Evaluation of phase, microstructural and mechanical characteristics in stir casted AA6351-Gr-TiC hybrid metal matrix composites

Abstract

The demand for advanced materials with enhanced mechanical properties for various engineering applications has spurred research into hybrid metal matrix composites. This study aims to explore the influence of incorporating Gr-TiC reinforcement particles into the AA6351 metal matrix. The fabrication process involved adding different weight percentages of Gr-TiC (0.5-0.5, 1.0-1.0, 1.5-1.5, and 2.0-2.0 wt%) to the AA6351 metal matrix using the liquid metallurgy technique. Comprehensive analyses were conducted on the fabricated samples to assess their phase, microstructure, EDS, density, hardness, tensile strength and fractured morphology. X-ray diffraction analysis showed that the interfacial bonding between the matrix and reinforcement particles caused a preparatory stage of development. Moreover, scanning electron microscopy confirmed that the reinforcement particles were uniformly distributed throughout the aluminum matrix. Due to the presence of graphite and porosity in the fabricated samples, the density of the aluminum metal matrix decreased. The samples with a reinforcement proportion of 2.0 wt% graphite and 2.0 wt% TiC exhibited the lowest density of 2.61 gram/cc. The maximum levels of hardness, engineering ultimate tensile strength, and true ultimate tensile strength were observed at a weight percentage of 1.0 wt% for both Gr and TiC, with values of 85 HRC, 206.7 N/mm2, and 260.43 N/mm2 respectively.