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The metal matrix composites are widely used in various engineering applications. The fabrication of MMCs with different wt. % of reinforcements helps to improve the mechanical and the wear properties. In this research work, different wt. % of ceramic reinforcements with Al-7075 alloy were used to fabricate the hybrid MMCs routed through liquid metallurgical technique. The hardness of the fabricated composites was measured using Vickers hardness tester. The obtained results revealed that the hardness values increased by increase in the wt. % of reinforcement. Wear behaviour of composites was studied using pin on disc wear test equipment under dry-sliding conditions. Experimental trials were carried out based on the Taguchi method. L27 OA (Orthogonal array) was used for investigation of the data. Effect of the wear parameters on the wear and coefficient of friction were studied using ANOVA technique. ANOVA results revealed that the wt. % of reinforcement has a substantial influence on wear loss and COF. Finally, the orthogonal array results were verified by conducting confirmatory tests. The wear mechanism of the worn-out surface was analysed using SEM and EDS analysis. [ABSTRACT FROM AUTHOR]

Having Low density and being Light weight with better mechanical properties, aluminum is the most significant material and is universally used in highly critical applications like navy, aerospace and particularly in automotive applications. This research work is aimed to investigate the effect of micro and nano Al2O3 (Alumina Oxide) to aluminium (Al) on the mechanical and wear properties of the Al composites. The micro - nano composites with 1, 2, 3 and 4 % of Al2O3 particulates in Al are fabricated using stircasting processes. It was found that an increase of Al2O3 both as micro and nano particulates content resulted in improved hardness, enhanced tensile strength and high wear resistance. However, nano Al2O3 reinforced MMCs have better hardness, improved tensile strength and higher wear resistance as compared with micro-sized Al2O3 reinforced MMCs. Grain refinement of composite and nano composite materials as compared with pure Al were observed in the microscopic structures. Analysis of wornout surface and tensile fracture surface was studied by SEM analysis to examine the nature of wear and tensile fracture mode of composite samples. [ABSTRACT FROM AUTHOR]

The Al2O3-SiC reinforced Al7075 Metal Matrix Composite (MMCs) is fabricated through liquid metallurgical technique. Ceramic particulates were amalgamated into the aluminium alloy to achieve improved mechanical properties and wear resistance. Al-7075/Al2O3/SiC hybrid MMCs were produced by reinforcing 2%, 3%, 4% and 5% of Al2O3 and 3%, 5% and 7% of SiC particles. Microstructural analysis was carried out to evaluate the uniform dispersal of reinforcing particulates within the base matrix. The output results indicate that the mechanical properties of the hybrid MMCs are enhanced by increase the wt. % of ceramic particulates. Tensile fractography results show the internal fracture structure of the tensile test specimens in which the particulates fracture and pullouts were observed. The wear characteristics of developed composites are studied using the pin-on-disc apparatus. The high wear resistance is observed at 5% Al2O3 + 7% SiC reinforced MMCs. [ABSTRACT FROM AUTHOR]