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Fabrication of aluminium (Al) composites by stir casting process is an effective method for fabrication of better quality of Metal Matrix Composites (MMCs). Stir casting technique is one of the most commonly accepted techniques. In this research work, al7075 / SiC+CeO2 hybrid MMCs have been fabricated with varying wt.% of SiC (2%, 4%, 6% and 8%) particulates and constant 5% of CeO2 particulates. The ascast alloy and hybrid composite were hot rolled at a temperature of 500°C. Whereas, both the ascast and hot rolled hybrid composite was subjected to micro-structural, mechanical and wear tests. Optical microscope analysis revealed uniform dispersal of hard particles with in the base matrix in case of both of ascast and hot rolled composites. Hot rolled MMCs showed enhancement of 22.64% of hardness when compared with ascast alloy with increasing reinforcement of 0-6 wt.% of SiC content. Tensile strength increases by 28.24% for hot rolled composites when compared to the as cast and other hybrid composites. Reduction of wear loss by 54.38% for hot rolled composites when compared to the as cast and other hybrid composites. A tensile and wear fractography result shows the internal fractured structure which was analysed using a SEM analysis. [ABSTRACT FROM AUTHOR]

High-strength composite materials have been created as a result of the rising need for materials to improve the performance of civil, aeronautical and marine components. Among these, Al Metal Matrix Composites are commonly used to meet engineering requirements. The present research works focuses on manufacturing and exploring Al7075 alloy micro-structure, mechanical and wear characteristics of Silicon Carbide (SiC) particulates with weight percentages of 3, 6 and 9 respectively. Al7075-SiC composites have been produced by using metallurgical route. The microstructural study revealed a uniform distribution of SiCp. The existence of SiC has been affirmed by Energy Dispersive Spectroscopy (EDS) analysis performed on the developed composite (Al7075-9 wt. % SiCp). To study the loss of wear, experiments were performed on a tribometer attached to a hard steel disk. The wear parameters were optimized using the central composite design in response to the surface technique. The obtained results indicated that the mechanical properties of composites improved when SiCp was added. The developed model effectively predicted the wear rate with 95% reliability and results of all models were confirmed by ANOVA (Analysis of Variance). [ABSTRACT FROM AUTHOR]

Aluminium composites are extensively used in several industries. The production of Metal Matrix Composite (MMCs) with varying wt. % of reinforcement/s leads to enhancement of wear and mechanical behavior properties. In the present work, varying wt. % of TiB2 and constant wt. % of CeO2 particulates were reinforced in Al6061 alloy to manufacture hybrid Al MMCs by Vortex (Stircasting) technique. Developed hybrid MMCs were hotrolled at 515°C of temperature. Hardness of hybrid MMCs was evaluated by using hardness test rig (Vickers). Results revealed that the hardness strength of developed hybrid MMCs increased with increase of the reinforcement content. The rate of wear of developed hybrid MMCs was evaluated by Pin-on-Disc wear test method. Test trials were conducted according to Taguchi technique. L27 array was implemented for evaluation of data. Effect of varying factors on the rate of wear and Coefficient of Friction (COF) was analyzed by applying ANOVA (Analysis of Variance) method. ANOVA outcomes showed that the reinforcement content had a more significant impact on wear behavior and COF of the MMCs. Finally, L27 array outcomes were verified through confirmation experiments. Wear fractography test shows the internal fractured structure of a wear specimen which was studied using a Scanning Electron Microscope (SEM). [ABSTRACT FROM AUTHOR]

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]

The effects of SiC (Silicon Carbide) - Al2O3 (Aluminium Oxide) particle in the Al alloy on the mechanical and wear characteristics of stir-casted Composites have been reported. The Al7075 is reinforced with 2, 4, 6 and 8 wt. % of reinforcements (SiC + Al2O3) to manufacture the hybrid composite. Ceramic particulates were added into Al alloy to achieve the low wear rate and improved mechanical properties. Hardening of cast specimens was done at 480ºC for the duration of 2 hrs and the specimens were quenched into two different quenching media (water and ice cubes). Finally, age-hardening was carried out at the temperature of 160ºC for the duration of 4 hrs and cooled at room temperature. The tensile strength, hardness and wear behaviour of MMCs (metal matrix composites) were evaluated on the un-treated and heat treated composite. The tensile strength and hardness of MMCs increased by incorporating SiC-Al2O3 particulates. The wear behaviour of the MMCs containing SiC-Al2O3 particulates revealed high wear-resistance. The heat-treatment had considerably improved the properties when compared to the non-heat treated composites. The composites with the highest tensile strength, hardness and enhanced wear resistance were found in the composites quenched in ice cubes. Worn-out surfaces of the composite specimens were studied by using SEM (Scanning Electron Microscopy) and EDS (Electron Dispersion Spectroscopy) analyses. [ABSTRACT FROM AUTHOR]