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 gra
phite (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 car
ried 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.