Al-7075 alloy-base matrix, reinforced with mixtures of silicon carbide (SiC) and boron carbide (B 4 C) particles, know as hybrid composites have been fabricated by stir casting technique (liquid metallurgy route) and optimized at different parameters like sliding speed, applied load, sliding time, and percentage of reinforcement by Taguchi method. The specimens were examined by Rockwell hardness test machine, Pin on Disc, Scanning Electron Microscope (SEM) and Optical Microscope. A plan of experiment generated through Taguchi's technique is used to conduct experiments based on L 27 orthogonal array. The developed ANOVA and the regression equations were used to find the optimum wear as well as coefficient of friction under the influence of sliding speed, applied load, sliding time and percentage of reinforcement. The dry sliding wear resistance was analyzed on the basis of "smaller the best". Finally, confirmation tests were carried out to verify the experimental results.

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Novel Al-6061 hybrid composite materials with varying range of SiC particulate and constant weight percentage of B4C particulate and 1% of magnesium alloy were fabricated by the stir casting technique (liquid metallurgy route). The mechanical and tribological properties of the hybrid composites and that of Al-6061 unreinforced alloy were examined by a Rockwell hardness test machine, pin-on-disc test machine, and Optical Microscope and Scanning Electron Microscope (SEM). A plan of experiment generated through Taguchi's technique was used to conduct experiments based on the L27 orthogonal array. The developed analysis of variance (ANOVA) and the regression equations were used to investigate the influence of parameters like sliding speed, applied load, sliding time, and percentage of reinforcement and their interactions on the dry sliding wear and friction coefficient of the composites. The motto of the present study is ‘the smaller the better’ to identify the optimum conditions for dry sliding wear and the friction coefficient. The results indicate that wear rate and friction coefficient were highly influenced by applied load, sliding speed, percentage of reinforcement and sliding time whereas the interaction between these parameters show only a minor influence in Hybrid Metal Matrix Composites (HMMCs). The wear surface morphology and wear mechanism of the pins were investigated using SEM and were correlated with wear test results. Finally, confirmation tests were carried out to verify the experimental results. It is concluded that Al-6061 hybrid composite can replace the conventional material used in the brake disc of automobiles owing to improved hardness and strength and reduced wear rate.

In this present study, a natural fiber-based fiber metal laminate (FML) was fabricated for various engineering applications. The primary aim of this present investigation was to study the effect of adding natural fiber along with metal and the effect of the surface-treatment process on the reinforcements on load-bearing and thermo-mechanical properties. Okra fiber woven mat, aluminum 2024-T3 foil and rice husk-derived biosilica were used as reinforcements.For surface treatment, the metal foil was sandblasted whereas the okra fiber and biosilica were silane-treated. The FML was fabricated using the vacuum bag method utilizing as-received and silane-treated reinforcements as two separate models. According to the results, the addition of Al foil and okra fiber improved the storage modulus and loss factor of about 4.2 GPa and 0.39 for surface-treated reinforcements. Similarly, maximum fracture toughness and energy release of 39.42 MPa √m and 0.76 MJ/m 2 for surface-treated EOA2 composite designation. Moreover, the addition of okra fiber and Al foil increased the fatigue life counts up to 54,266, 48,116, and 26,263 for surfacetreated EOA2 composite at 30%, 60%, and 90% of ultimate tensile stress (UTS).Such thermo-mechanical and load-bearing properties improved FMLs could be used in automotive, aircraft, drone and other industrial applications requiring high structural rigidity and load absorbing capability.

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