Characterization of AA6063/SiC-Gr Surface Composites Produced by FSP Technique

Friction stir processing (FSP) is a novel technique used for the production of surface composite, refinement of microstructure and enhancing the mechanical properties. In this work, surface matrix composite (SMC) was fabricated on the surface of aluminium alloy (6063) with ceramic reinforcement using friction stir processing technique. SiC and Gr was used as reinforcement. The chosen FSP parameters such as traverse speed of 30 mm/min, tool rotational speed of 1000 rpm and 10 KN of axial load. The FSP tool made of HcHCr with cylindrical threaded profile pin having shoulder diameter of 18 mm, pin length of 5.8 mm and pin diameter of 6 mm was used. The FSP was carried out using friction stir welding machine. Three combinations of surface composites (Al/0.8Vol.%SiC, Al/0.8Vol.%Gr and Al/0.4Vol.%SiC-0.4Vol.%Gr) were fabricated. Optical microscope (OM) and scanning electron microscope (SEM) was used to study the microstructural changes. The recrystallized grain structure was observed in the FSPed zone. The microhardness of friction stir processed plates was analyzed using a Vickers hardness tester. Sic reinforced Al alloy surface composite resulted higher microhardness.