Development of Functionally Graded Tubes Based on Pure Al/Al₂O₃ Metal Matrix Composites Manufactured by Centrifugal Casting for Automotive Applications

This paper studies the influence of main parameters on the mechanical properties and wear behaviour of functionally graded materials pure Aluminum reinforced by various weight fractions of aluminium oxide (Al₂O₃). A Functionally graded (FG) pure aluminium/Al₂O₃ tube was processed by horizontal centrifugal casting method. The hollow tube dimensions are 230 mm outer diameter x 12 mm thickness x 180 mm length. The properties of these FG tubes were compared with unreinforced alloy. Hardness and tensile results in the radial direction showed that the hardness and tensile in accordance with the gradient microstructure was improved from inner zone to outer zone. Wear tests were carried out for different test duration at a constant sliding speed of 8 m/s and loads applied are 14, 24 and 40 N. In all test conditions the wear rate in the outer layer was minimum compared to other layers. In the surface analysis, scanning electron microscope indicated the presence of delamination, wear debris and cracks. FG tubes reinforced by Al₂O₃ particles have increased mechanical properties and wear resistance compared to its unreinforced alloy (matrix alloy) and is suitable for use in automobile and transport applications.