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Investigating mechanical and physical properties of stir casted Al6061/nano Al2O3/quartz hybrid composite

Tirfe Dagim, Woldeyohannes Abraham, Hunde Bonsa, Batu Temesgen, Geleta Eaba

Advances in Mechanical and Materials Engineering

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2023

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Vol. 40, nr 1

189-201

EN

Aluminum alloys are widely used in different engineering application areas, such as aerospace, automotive, and marine industries. However, their properties need some improvement in order to enlarge their application area. Thus, the objective of the study was to improve the physical and mechanical properties of Al6061 aluminum alloy by reinforcing it with nano-Al2O3 and micro-quartz particles. The investigation primarily was focused on studying the impact of quartz particles on the mechanical and physical properties of an Al6061/nano Al2O3/quartz hybrid composite. The hybrid composite was developed using a stir casting technique, by varying the weight percentage of quartz particles at 3%, 6%, and 9%, while maintaining a constant weight percentage of nano-Al2O3 at 3.5%. To evaluate the composite's properties, test samples were prepared according to ASTM E9-09 and ASTM E23 standards for hardness, compressive strength, creep, and impact energy absorption, respectively. The results of the investigation demonstrate that, with the addition of 9 wt.% of micro-quartz particles and 3.5 wt.% of nano-Al2O3 nanoparticles, all mechanical and physical properties of the matrix were improved, except for the impact strength. Based on these results, the developed hybrid composite material can be recommended for light weight automotive spare parts such as brakes and clutch discs.

PL

Stopy aluminium są szeroko stosowane w różnych obszarach zastosowań inżynieryjnych, takich jak przemysł lotniczy, motoryzacyjny i morski. Właściwości stopów aluminium wymagają udoskonaleń, aby zwiększyć zakres ich zastosowań. Celem badań była poprawa właściwości fizycznych i mechanicznych stopu aluminium Al6061 poprzez wzmocnienie nanocząstkami Al2O3 i cząstkami mikrokwarcu. Badania skupiały się przede wszystkim na badaniu wpływu cząstek kwarcu na właściwości mechaniczne i fizyczne kompozytu hybrydowego Al6061/nano Al2O3/kwarc. Kompozyt hybrydowy opracowano techniką odlewania z mieszaniem, zmieniając udział wagowy cząstek kwarcu na 3%, 6% i 9%, utrzymując natomiast stały udział wagowy nanocząstek Al2O3 (3,5%). Do oceny właściwości kompozytu, przygotowano próbki testowe zgodnie z normami ASTM E9-09 i ASTM E23 dotyczącymi odpowiednio twardości, wytrzymałości na ściskanie, pełzania i pochłaniania energii uderzenia. Wyniki badań wykazały, że dodatek 9% kwarcu i 3,5% nanocząstek Al2O3 spowodował poprawę wszystkich właściwości mechanicznych i fizycznych osnowy, z wyjątkiem udarności. Na podstawie uzyskanych wyników, opracowany hybrydowy materiał kompozytowy może być zalecany do lekkich części zamiennych do samochodów, takich jak tarcze hamulcowe i sprzęgła.

2

Hardness and dry sliding wear behaviour of Al7050 hybrid composites produced by stir casting

Srivallirani Katepalli, Venkateswara Rao M

Composites Theory and Practice

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2022

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R. 22, nr 3

150--159

EN

Hardness and dry sliding wear behaviour of Al7050 hybrid composites produced by stir casting The current study aims to investigate at the tribological properties of Al7050 reinforced with TiO2 and BN particles utilising a pin-on-disc apparatus. By means of the stir-casting process, MMCs were fabricated with three different weight percentages of TiO2 particles: 1, 3, and 5%, as well as various weight percentages of h-BN particles: 2, 4, and 6%. The volumetric wear rates and coefficients of friction were continuously recorded under normal loads of 20-40 N, sliding speeds of 2-4 m/s and for sliding distances of 1000, 1500 and 2000 m. Microstructural analysis revealed that the TiO2 and BN particles were uniformly dispersed throughout the Al7050 matrix with minimal agglomeration. The experimental data reveals that the tensile strength and Vickers hardness of the cast hybrid composites gradually improved by increasing the weight percentages of the TiO2 and h-BN reinforcing particles. The worn micrographs reveal that abrasion and delamination are the dominant wear mechanisms in the case of the hybrid composites. The composite containing 6 wt.% h-BN particles had the lowest coefficient of friction and wear rate at a normal load of 40 N, sliding speed of 4 m/s and for the sliding distance of 2000 m when compared to other composites. On the other hand, the composites with 2 wt.% h-BN particles had the highest coefficient of friction and wear rate. The XRD analysis showed the generation of strong interfacial reactions, which contributed to the hardness of the hybrid composites.

3

Modelling and optimization of wear parameters of Al 4032 reinforced with coal ash using Taguchi and RSM approach

Gudimetla Avinash, Lingaraju Dumpla, Sambhu Prasad S.

Composites Theory and Practice

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2021

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R. 21, nr 1-2

3--11

EN

The present study aimed to analyze the wear behaviour of composites synthesized by reinforcing Al 4032 with 2, 4, 6 wt.% of coal ash using the stir casting technique. Wear testing was performed on the composites at room temperature in the absence of lubrication using a pin-on-disc tribometer considering the process parameters as wt.% of reinforcement, speed and load. Micro structural characterization using scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX) was performed on the cast composites to ascertain the existence of the reinforcement along with its distribution in the prepared composites. The Taguchi L16 orthogonal array was utilized to design experiments to study the significance of the process parameters on the wear rate. A mathematical model was developed for the wear rate using response surface methodology (RSM). 6 wt.% reinforcement, at the speed of 100 rpm and 10 N load were the obtained optimized parameters for the minimum wear rate. Surface plots as well as contour plots were analyzed to understand the consequence of the process parameters on the wear rate. The analysis of variance (ANOVA) revealed that speed with 76.10 % was the most prominent parameter followed by load and reinforcement with 11.23 and 9.42% respectively.

4

Experimental investigation and optimization of mechanical properties of nitinol reinforced composites

Kalepu Sambasivarao, Nallu Ramanaiah

Composites Theory and Practice

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2021

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R. 21, nr 4

154--160

EN

Metal matrix composites (MMCs) have elevated properties when compared to their parent metals. Aluminium, due to its light weight has a versatile set of applications. In the present work, the 2024 aluminium alloy was chosen as the metal matrix, was melted and stir cast at a temperature of around 900°C along with an addition of a nickel-titanium (Ni-Ti) in powder form as the reinforcement in varying proportions (2, 4, 6, 8% weight fractions). Tests were conducted to analyse the tensile strength, impact strength, elongation and microstructure of the produced specimens. SEM micrographs revealed that the MMCs with 2 and 4 wt.% reinforcement exhibited better dispersion of the reinforcement. The composites having the 4 and 6 wt.% additions of Ni-Ti powder exhibited better ultimate tensile strength when compared to the other specimens, whereas the one with the 8 wt.% addition of Ni-Ti powder revealed better impact strength. Some agglomerations of the Ni-Ti particles were observed on the fractured surface. When evaluating the optimum result using design expert or the design of experiments, it is understood that when the data points are evenly split, either transformation or a higher order model can improve the fit to obtain the optimum result. The yield strength of the metal matrix composite which indicates the ability of the material to withstand permanent deformation varies with respect to the additions of Ni-Ti powder. It occurred that the MMCs with the 4 and 6 wt.% reinforcement produced better results when compared with the 2 and 8 wt.% ones, respectively. The impact strength of the composite containing the 8 wt.% addition exhibited better resistance when compared with the 2, 4 and 6 wt.% reinforced MMCs. It was revealed that the 8 wt.% addition of Ni-Ti powder to the metal matrix resisted fracture due to the applied load. The lower limit for the ultimate tensile strength is 186 MPa and for the upper limit it is 212.14 MPa, which are within the acceptable range; therefore, the optimum results are within the limits.

5

Effect of tungsten carbide on Al6061/SiC hybrid metal matrix composites

Vijay P, Brahma Raju K.V., Ramji K., Kamaluddin S

Composites Theory and Practice

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2021

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R. 21, nr 4

169--180

EN

Aluminium matrix composites (AMC) are mostly preferred for their high specific strength, high ductility, corrosion resistance and creep resistance. Various experimental investigations are conducted in the field of AMCs, which are widely applicable in several fields like aerospace (especially aircraft structures and fittings), marine fittings, automotive industries (connecting rods, pistons, brake rotors, and engine blocks), etc. The current work presents the effect of a tungsten carbide (WC) reinforced Al6061/SiC hybrid composites. In this study, the WC particle (3÷5 μm) content is varied from 0 to 6 wt.% in steps of 2 wt.%, while keeping the SiC particle (63 μm) content of 5 wt.% constant. The stir casting method was used to prepare these composites and the behaviour of the composites was studied to ascertain their mechanical and corrosion properties. From the obtained results, it was observed that the ultimate tensile strength, hardness, and corrosion resistance of the composites are enhanced by increasing the content of WC, whereas the wear loss (microns) decreased as the WC was increased up to 4 wt.%; later it increased drastically at 6 wt.% WC. The corrosion results reveal that the corrosion rate of the composites is lower than that of the monolithic alloy. SEM examination of the tensile fracture surface shows that there is a formation of larger shear lips in the base alloy and the composite with 5 wt.% SiC; however, they are reduced gradually by the additions of WC to the composite. The microstructure of the corroded surfaces reveals that the pit density was reduced for the composite with 6 wt.% WC compared to the other composites.

6

Investigation of mechanical and tribological behavior of Al 4032-SiHGM MMC

Gudimetla Avinash, Lingaraju D., Prasad S. Sambhu

Composites Theory and Practice

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2020

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R. 20, nr 3-4

142--156

EN

The present study is aimed at identifying the influence of silicon hollow glass microspheres (SiHGM) on a newly engineered metal matrix composite. Silicon micro balloons of various wt.% (2, 4, 6) are reinforced in to aluminium 4032 to produce a composite using the stir casting technique. The mechanical properties of the composite such as hardness, tensile and compressive strength were measured. The dry sliding wear test was conducted on the produced specimens to measure the wear rate and coefficient of friction. The results revealed that the properties of the composite are better with an increase in the wt.% of reinforcement. The presence of reinforcement in the composites was identified using Energy Dispersive X-Ray analysis (EDX). The grain boundaries and grain refinement for various compositions of reinforcements and worn surfaces were analyzed using Scanning Electron Microscope (SEM) micrographs. The process parameters for the minimum wear rate and coefficient of friction were identified and optimized by using the Taguchi L16 orthogonal array. Analysis of variance (ANOVA) was used to determine the percentage contribution of each process parameter. Multi-response optimization was carried out using Grey relational analysis (GRA) to optimize the process parameters to attain a minimum coefficient of friction and wear rate. The variation in wear rate and coefficient of friction are analyzed with respect to reinforcement (wt.%), speed (rpm) and load (N).

7

Synthesis of metal matrix composites through stir casting process - a review

Sakthivelu S., Sethusundaram P. P., Meignanamoorthy M., Ravichandran M.

Mechanics and Mechanical Engineering

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2018

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Vol. 22, nr 1

357--369

EN

Metal is the one of the important material in engineering materials because of their high strength to weight ratio. However the pure metals cannot be used as engineering materials due to their ductile property. So, to improve their mechanical properties, some of the high strength materials (not metals) were added as reinforcement to improve the mechanical properties of pure metals and the newly developed material is called as metal matrix composites. At present, Aluminium, Copper, Magnesium, Titanium and Iron have been used as matrix materials and materials like TiC, SiC, B4C, WC, Cr3C, TiO2, ZrO2, Gr, MoS2 and Si3N4 have been used as reinforcements. There are many processing techniques to fabricate metal matrix composites namely stir casting, ultra-sonic assisted casting, compo-casting, rheo casting, powder metallurgy technique, etc,. Among these, stir casting process is the most suitable and economical method to fabricate the metal matrix composites. In this article, an effort has been made to review the work of various researchers to fabricate metal matrix composites through stir casting process.