In this work, functionally graded materials were synthesized by centrifugal technique at different volume fractions (0, 0.5, 1, 1.5, and 2% Vf) with different rotational speed of (0, 600, 800, 1000 and 1200) r.p.m and different rotational time (0, 1, 2, 3 and 4) min. The hardness and tribological properties were characterized to study the graded and non-graded nanocomposites and the pure epoxy material. Using a pin-on-disc machine, sliding wear tests are conducted with the following parameters: rotation speed (400 rpm), normal load (30 N), filler content (0–2% Vf), and sliding distance (0.15 km). The hardness and wear parameters of graded composites were investigated and compared to those of epoxy composites with homogeneous filling. This work demonstrates that incorporating Al2O3 nanoparticles improves graded composites' hardness and sliding wear resistance. Epoxy–Al2O3 epoxy composites with a volume fraction of 2 had the lowest specific wear rate of all samples. The FGMs had superior sliding wear performance compared to homogenous composites. The maximum difference in hardness and coefficient of friction occurred at (FGM), which is loaded from the rich side of the nanoalumina at (Vf = 2%, N = 1200 r.p.m and T = 6 min), where the maximum value was 168% and 78 % as compared with neat epoxy, respectively. The wear rate of the functionally graded samples was enhanced by (87.7%) compared with neat epoxy if loaded from the alumina-rich side.

In this work, functionally graded materials were synthesized by centrifugal technique at different volume fractions 0.5, 1, 1.5, and 2% Vf with a rotation speed of 1200 rpm and a constant rotation time, T = 6 min . The mechanical properties were characterized to study the graded and non-graded nanocomposites and the pure epoxy material. The mechanical tests showed that graded and non-graded added alumina (Al2O3) nanoparticles enhanced the effect more than pure epoxy. The maximum difference in impact strength occurred at (FGM), which was loaded from the rich side of the nano-alumina where the maximum value wasat 1% Vf by 133.33% of the sample epoxy side. The flexural strength and Young modulus of the functionally graded samples were enhanced by 43.69% and 52.74%, respectively, if loaded from the alumina-rich side. On the other hand, when loading (FGM) from the epoxy side, the amount of decrease in bending resistance was 122.4% while the improvement in bending modulus was 81.11% compared to pure epoxy. Scanning electron microscopy (SEM) revealed the fracture surface of the impact samples and the gradient scattering of nanoparticles in the epoxy matrix. Numerous applications can be used to manufacture the functionally graded material by centrifugal casting method, including for the manufacture of gears and all bending applications such as leaf springs.