Wear analysis and optimization of nanoclay and copper coated carbon fiber strengthened hybrid aluminium composite

Abstract

• AA6026 alloy is reinforced with copper-coated carbon fibers (4 wt.%) and nanoclay (1-5 wt.%) by compocasting to enhance performance. • The wear test was conducted by adopting a Taguchi's L25 orthogonal array and G99 standards, revealing that higher sliding speeds lead to a reduction in wear loss, friction coefficient, and friction force. • The addition of 3 wt% nanoclay improves wear resistance due to an increased surface area; however, an excessive amount of nanoclay results in performance deterioration due to agglomeration. Although aluminium alloys have superior weight to strength ratios, they significantly lose some of their qualities at lower temperatures, hence reinforcements are done to improve its characteristics for wider applications. In this work, AA6026 alloy is incorporated with 4 wt. % of copper coated carbon fibers (CF) and varying proportions of nanoclay (1, 2, 3, 4, and 5 wt. %), fabricated via the compocasting technique. Wear test was performed by adopting a L 25 orthogonal array (OA) based on Taguchi's experimental design based on ASTM G99 standards. As sliding speed increases, wear loss, the friction coefficient, and the friction force all reduce due to the improved strength with the addition of 3 wt. % of nanoparticles due to higher volume to surface area, similarly with higher axial load, the outputs tend to reduce. Higher additions of nanoclay lower the wear performance due to agglomeration. When compared with 3 wt. % of nanoclay addition, the wear loss is higher by 15.65%, 4.76%, 12.72%, and 24.08% for 1, 2, 4, and 5 wt. % nanoclay addition, respectively. The ANOVA reveals that sliding speed was the most significant factor, contributing 74.88% to the grey relational grade (GRG), 10.09% to the nanoclay reinforcement, and 8.32% to the axial load, with an R 2 value of 95.21%. The predicted GRG (0.973) lies within the computed confidence interval (CI) values of 0.790 and 1.156. SEM micrographs reveal microcracks on the surface, along with ploughing and abrasive wear mechanisms. The adopted metaheuristic nature-inspired evaporation rate-based water cycle algorithm yields identical results and quickly converges to optimal conditions, resulting in a combined objective function of 157.67.

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