Thermal Enhancement of Stir-Casted Al6061-Cu Metal Matrix Composite Fins: Experimental Evaluation Under Forced Convection

The thermal performance of aluminium fins is essential for improving heat dissipation in compact heat exchange systems. Conventional Al6061 fins exhibit restricted thermal conductivity, which limits their efficiency in forced convection environments. This research examines the thermal enhancement of stir-cast Al6061-Cu Metal Matrix Composite (MMC) fins, which are reinforced with 5%, 10%, and 15% copper by weight. The composites were produced through a controlled stir- casting process, maintaining a stirring speed of 400 rpm for a duration of 10 minutes to achieve uniform particle dispersion. A thermal evaluation was performed utilising a pin-fin apparatus under forced convection, maintaining a constant heat input of 15 W and an air velocity of 4.2 m/s. The pure Al6061 fin demonstrated a heat transfer coefficient (h) of 24.57 W/m²K, which increased to 25.33 W/m²K, 25.72 W/m²K, and 26.20 W/m²K for 5%, 10%, and 15% Cu composites, reflecting improvements of 3.08%, 4.66%, and 6.23%, respectively. The heat transfer rate increased from 11.75 W for pure Al6061 to 12.56 W for the 15% Cu specimen, indicating a 6.89% improvement. The Al6061-Cu MMC fin containing 10-15% Cu exhibited optimal manufacturability and performance, validating copper reinforcement as a viable approach for enhancing lightweight thermal management systems.