Issue 75

G. U. Raju et alii., Fracture and Structural Integrity, 75 (2026) 281-296; DOI: 10.3221/IGF-ESIS.75.20

Figure 5: Elemental analysis of the AA7076 composites reinforced with 1 wt. % perlite nanoclay (Top) and 1.5 wt. % perlite nanoclay (Bottom).

M ECHANICAL BEHAVIOUR OF NANOCLAY COMPOSITE

Hardness ig. 6 illustrates the Vickers hardness of AA7076 composite reinforced with varying weight percentages of perlite nanoclay, providing valuable insights into the impact of these reinforcements on the material's properties. The Vickers hardness of the base material was found to be 82 HV. The addition of perlite nanoclay substantially enhanced the hardness of the AA7076 composite, indicating improved resistance to deformation. Composite loaded with 1 wt.% and 1.5 wt.% perlite nanoclay reinforcement exhibited an enhancement in hardness by 17% and 32% respectively, compared to the aluminium alloy. Increasing the concentration of reinforcement particles positively influences hardness, with the 1.5 wt.% composite exhibiting the highest hardness. The enhanced hardness is attributed to the homogeneous distribution of perlite nanoclay reinforcement around the grain boundaries of AA7076 alloy. Perlite nanoclay particles act as load-absorbing agents, contributing to the ability of the composite to withstand deformation under stress. Similar hardness improvements have been reported in other aluminium-based nanocomposites. Patel et al. [5] observed a 40% increase in hardness in AA5052/SiC composites, while Ravikumar et al. [12] reported a 28% increase in AA7075 reinforced with hybrid Al 2 O 3 particles. Harichandran and Selvakumar [11] also demonstrated that the addition of B 4 C nanoparticles significantly improved hardness due to their role in restricting dislocation motion. F

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