Synergistic enhancement of microstructure and tribo-mechanical performance in high-entropy alloy reinforced functionally graded lightweight composite

This work emphasizes on development of the LM13 Al alloy based functionally graded composite (FGC) reinforced with AlTiVZrCrMo high entropy alloy (HEAs) fabricated through centrifugal casting. The AlTiVZrCrMo HEA powders are prepared by high-energy ball milling and added at 10 wt% to achieve a graded microstructure along the radial direction in a hollow cylindrical component with dimensions of ø out 100 x ø in 85 x 100 mm. Microstructural analysis revealed refined grains and enrichment of HEA reinforcement in the outer region of the Al/FGC. In relation with LM 13 alloy, the Al/FGC exhibited significant improvements in hardness of 9.18%, 11.76%, and 21.78% and tensile strength of 27.85%, 34.36%, and 44.05% in the inner, middle, and outer regions, respectively. Wear studies revealed that the outer region of Al/FGC achieves the lowest SWR (5.8 ⨯ 10 −3 , 3.4 ⨯ 10 −3 , 4.6 ⨯ 10 −3 mm 3 /Nm) and COF (0.47, 0.36, 0.39) under maximum applied load (A.L), sliding distance (S.D), and sliding velocity (S.V) conditions, respectively, compared with other samples. The tribological parameters influence the response in the following order: A.L > S.V > S.D. The improved wear resistance of the outer region was evidenced by the occurrence of cavities, grooves, microcracks, and delamination on the worn surface.