Surface fracture analysis of stir casted AA 6063/TiC/Gr hybrid composites under different solidification rate

Aluminium Alloys (AA) are predominantly used in various fields of engineering applications. Among that the AA 6000 series is mostly preferred material for automobile applications. In this research work, the AA 6063 is selected as the matrix material and it is reinforced with Titanium Carbide (TiC) of 10 wt% and graphite (Gr) of 3 wt% using the liquid stir casting technique. The solidification is done with four different cooling rates for the composites and its effects on mechanical properties are analyzed. The hardness of the AA 6063/TiC/Gr hybrid composites is increased with an increase in cooling rate but the compressive strength is decreased because of the phenomenon of brittle transition. The higher tensile strength of AA 6063/TiC/Gr hybrid composite is achieved for the cooling rate of 3 °C/s. The microscopic analysis is carried out using the Scanning Electron Microscopy (SEM) for the tensile tested samples. From SEM images, it is inferred that the grains are refined and leads to brittle transition at the surface of composites.