We report the fabrication of alumina (Al2O3) and silicon carbide (SiC) particulates reinforced Al metal matrix composites (Al MMCs) by stir casting method. The effect of reinforcement and heat treatment on the corrosion properties of Al matrix and r-Al MMCs were investigated by polarization, impedance and weight loss methods. Taguchi's experimental design method was employed to set the process parameters. In order to find the optimal process parameter levels, orthogonal arrays of Taguchi, the signal-to-noise (S/N) ratio, the analysis of variance (ANOVA), and regression analyses were employed. The analysis on the effect of these parameters on the corrosion rates has also been discussed. The results revealed that the rate of corrosion decrease with increase in the content of Al2O3 and SiC particulates in the r-Al MMCs. A significant enhancement in the corrosion resistance was observed with heat treated of Al alloy and its composites. The morphological analysis by SEM micrographs revealed the lesser formation of cavities due to corrosion upon the increase in Al2O3 content which would be beneficial for corrosive application.

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 automotive activities. This research work is aimed to investigate the effect of micro and nano boron 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 an 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 from the microscopic images. Analysis of wornout surface and tensile fracture surface were studied by SEM analysis to examine the nature of wear and tensile fracture mode of composite samples.

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The Al2O3-SiC reinforced Al7075 Metal Matrix Composite (MMCs) is fabricated through liquid metallurgical technique. Ceramic particulates were amalgamated into 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 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 pin on disc apparatus. The high wear resistance is observed at 5% Al2O3 + 7% SiC reinforced MMCs.

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