Dynamic mechanical and microstructural analysis of graphite-reinforced Al6061 alloy processed by friction stir processing
K. Venkateswara Reddy, Guttikonda Manohar
Abstract
The current research focuses on enhancing the damping capacity of the Al6061-T6 alloy to eliminate vibrations by introducing graphite (Gr) particles into its surface using friction stir processing (FSP). FSP was conducted using a tool with a conical pin of 4 mm in length and a shoulder diameter of 15 mm. The process parameters selected were a traverse speed of 30 mm/min and a rotating speed of 900 rpm. The microstructure and Gr distribution within the samples were analyzed using optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy. After processing, surface composite hardness decreased by 26%. This was attributed to the Gr softness when compared to matrix metal. Samples were taken from the stir zone (SZ), and damping characteristics were examined using the dynamic mechanical analyzer. Compared to the base metal, the damping capacity of the Al/Gr composite is enhanced by 3.5 times. The active damping mechanisms in the Gr-reinforced composite were studied, and microstructural modification was observed in the SZ.