Influence of gradation in the reinforcement particles on the interfacial microstructure and mechanical properties of functionally graded composites

Abstract

In this research, Al6061 alloy-based Functionally Graded Composites (FGCs) were fabricated by hot pressing which is composed of 7 layers with different proportions of Al2O3 reinforcement particles. The addition of Al2O3 particles is gradually increasing in the other layers from top to bottom (Layer 1 -Pure Al6061 alloy, Layer 2-5 wt % Al2O3, Layer 3-10 wt% Al2O3, Layer 4-20 wt% Al2O3, Layer 5-30 wt% Al2O3, Layer 6-40 wt% Al2O3, Layer 7-50 wt% Al2O3). Moreover, three different Al2O3 particle sizes (8, 16 and 32 mu m) were used to fabricate three sets of FGCs. Reciprocating wear studies were performed and the result shows that the FGC with 8 mu m Al2O3 particle size shows 85.5% improved wear resistance. Further, various wear mechanisms were investigated and finally compressive strength analysis proved that the homogenous distribution of Al2O3 particles in the FGC with 16 mu m Al2O3 particle size helps achieve the maximum compression stress of 476.04 MPa compared with other FGCs.