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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]