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Investigation of The Effect of Mechanical Vibration Applied During Solidification on The Microstructure and Properties of Aluminum 356 Alloy

Özgü Taha Süreyya, Çalın Recept, Tanış Naci Arda

Archives of Foundry Engineering

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2024

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Vol. 24, iss. 1

26--31

EN

Manufacturing by casting method in aluminum and its alloys is preferred by different industries today. It may be necessary to improve the mechanical properties of the materials according to different industries and different strength requirements. The mechanical properties of metal alloys are directly related to the microstructure grain sizes. Therefore, many grain reduction methods are used during production or heat treatment. In this study, A356 alloys were molded into molds at 750°C and exposed to vibration frequency at 0,8.33, 16.66, 25, and 33.33 Hz during solidification. Optical microscopes images were analyzed in image analysis programs to measure the grain sizes of the samples that solidified after solidification. In addition, microhardness tests of samples were carried out to examine the effect of vibration and grain reduction on mechanical behavior. In the analyzes made, it was determined that the grain sizes decreased from 54.984 to 26.958 μm and the hardness values increased from 60.48 to 126.94 HV with increasing vibration frequency.

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Prediction of Fracture Stress with Regard to Porosity in Cast A356 Alloy

Sahin H., Atik M., Tezer F., Temel S., Aydin O., Kesen O., Gursoy O., Dispinar Derya

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 4

21--28

EN

Production of the defect-free casting of aluminium alloys is the biggest challenge. Porosity is known to be the most important defect. Therefore, many cast parts are subjected to several non-destructive tests in order to check their acceptability. There are several standards, yet, the acceptance limit of porosity size and distribution may change according to the customer design and requirements. In this work, the aim was targeted to evaluate the effect of size, location, and distribution of pores on the tensile properties of cast A356 alloy. ANSYS software was used to perform stress analysis where the pore sizes were changed between 0.05 mm to 3 mm by 0.05 mm increments. Additionally, pore number was changed from 1 to 5 where they were placed at different locations in the test bar. Finally, bifilms were placed inside the pore at different sizes and orientations. The stress generated along the pores was recorded and compared with the fracture stress of the A356 alloy. It was found that as the bifilm size was getting smaller, their effect on tensile properties was lowered. On the other hand, as bifilms were larger, their orientation became the dominant factor in determining the fracture.

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Effect of Chip Amount on Microstructural and Mechanical Properties of A356 Aluminum Casting Alloy

Kaya A. Y., Özaydın O., Yağcı T., Korkmaz A., Armakan E., Çulha O.

Archives of Foundry Engineering

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2021

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Vol. 21, iss. 3

19--26

EN

Aluminum casting alloys are widely used in especially automotive, aerospace, and other industrial applications due to providing desired mechanical characteristics and their high specific strength properties. Along with the increase of application areas, the importance of recycling in aluminum alloys is also increasing. The amount of energy required for producing primary ingots is about ten times the amount of energy required for the production of recycled ingots. The large energy savings achieved by using the recycled ingots results in a significant reduction in the amount of greenhouse gas released to nature compared to primary ingot production. Production can be made by adding a certain amount of recycled ingot to the primary ingot so that the desired mechanical properties remain within the boundary conditions. In this study, by using the A356 alloy and chips with five different quantities (100% primary ingots, 30% recycled ingots + 70% primary ingots, 50% recycled ingots + 50% primary ingots, 70% recycled ingots + 30% primary ingots, 100% recycled ingots), the effect on mechanical properties has been examined and the maximum amount of chips that can be used in production has been determined. T6 heat treatment was applied to the samples obtained by the gravity casting method and the mechanical properties were compared depending on the amount of chips. Besides, microstructural examinations were carried out with optical microscopy techniques. As a result, it has been observed that while producing from primary ingots, adding 30% recycled ingot to the alloy composition improves the mechanical properties of the alloy such as yield strength and tensile strength to a certain extent. However, generally a downward pattern was observed with increasing recycled ingot amount.

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Evolution of Aluminium Melt Quality of A356 After Several Recycling

Gursoy O., Erzi E., Tur K., Dispinar D.

Archives of Foundry Engineering

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2020

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Vol. 20, iss. 4

61--66

EN

Recyclability is one of the great features of aluminium and its alloys. However, it has been typically considered that the secondary aluminium quality is low and bad. This is only because aluminium is so sensitive to turbulence. Uncontrolled transfer and handling of the liquid aluminium results in formation of double oxide defects known as bifilms. Bifilms are detrimental defects. They form porosity and deteriorate the properties. The detection and quantification of bifilms in liquid aluminium can be carried out by bifilm index measured in millimetres as an indication of melt cleanliness using Reduced Pressure Test (RPT). In this work, recycling efficiency and quality change of A356 alloy with various Ti additions have been investigated. The charge was recycled three times and change in bifilm index and bifilm number was evaluated. It was found that when high amount of Ti grain refiner was added, the melt quality was increased due to sedimentation of bifilms with Ti. When low amount of Ti is added, the melt quality was degraded.

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Using Anthropogenic Waste (Steel Slag) to Enhance Mechanical and Wear Properties of a Commercial Aluminium Alloy A356

Sridhar Raja K. S., Bupesh Raja V. K., Gupta Manoj

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 1

279--284

EN

The present study addresses the utilization of induction furnace steel slag which is an anthropogenic waste, for enhancing the mechanical properties of a commercial aluminium alloy A356. Different weight percentage (3wt%, 6wt%, 9wt%, and 12wt%) of steel slag particles in 1 to 10 μm size range were used as reinforcing particles in aluminium alloy A356 matrix. The composites were prepared through stir casting technique. The results revealed an improvement in mechanical properties (i.e. microhardness and tensile strength) and wear resistance with an increase in weight percentage of the steel slag particles. This research work shows promising results for the utilization of the steel slag for enhancing the properties of aluminium alloy A356 at no additional cost while assisting at same time in alleviating land pollution.

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Investigation and prevention of the residues formed in melting furnaces and transfer ladles used in low-pressure Al-casting technologies

Yay B., Akinci E., Güneren A., Karaali U., Çubuklusu H. E., Çe B.

Journal of Achievements in Materials and Manufacturing Engineering

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2016

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Vol. 78, nr 1

5--10

EN

Purpose: Refractory life, in Al-casting processes such as alloy wheel production, is obviously affected by the inclusions formed in the transfer ladles and holding/melting furnaces in which melting, fluxing and degassing operations are carried out. The short refractory life affects, adversely, the economical aspect of the process. Therefore, a study on the physical and chemical properties of the above mentioned inclusions has been started. The main purpose of the study is to understand the relationships among the metallurgical processes taking place during casting, properties of the refractories used and the formation of inclusions. Design/methodology/approach: During this industry-university joint study, experimental studies using scanning electron microscopy (SEM), X-ray diffractometry (XRD) and optical microscopy were used to investigate the nature and properties of the inclusions. Also, corrosion behaviour of six different refractories was investigated by exposing them to molten aluminium.

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Prediction of mechanical properties of cast A356 alloy as a function of microstructure and cooling rate

Shabani M. O., Mazahery A.

Archives of Metallurgy and Materials

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2011

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Vol. 56, iss. 3

671-675

EN

In order to predict the mechanical properties of A356, a relatively new approach is presented in this paper using finite element technique which combines mechanical properties data in the form of experimental and simulated microstructures. In this work, the comparison of this model's predictions with the ones in the literature is presented. It is revealed that predictions of this study are consistent with the other works and experimental measurements for A356 alloy. The results of this research were also used in order to form an analytical equations followed with solidification codes for SUT (Sharif University Technology) software.

PL

W celu prognozowania właściwości mechanicznych stopów A356, w pracy przedstawiono stosunkowo nowe podejście przy użyciu metody elementów skończonych, które łączy w sobie dane właściwości mechanicznych w formie badań eksperymentalnych i symulacji mikrostruktur. W pracy przedstawiono porównanie przewidywań tego modelu z danymi literaturowymi i stwierdzono, że są one zgodne z innymi pracami i danymi eksperymentalnymi dla stopu A356. Wyniki tej pracy zostały również wykorzystywane do sformułowania równań analitycznych następnie użytych do programowania krzepnięcia w oprogramowaniu SUT (Sharif University of Technology).

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Microstructural and mechanical properties of gravity-die-cast A356 alloy inoculated with yttrium and Al-Ti-B grain refiner simultaneously

Lim Y. P., Ooi J. B., Wang X.

Archives of Foundry Engineering

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2011

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Vol. 11, iss. 4

77-82

EN

In the present work, the effect of inoculating yttrium and Al-5Ti-1B simultaneously on A356 aluminum alloy has been studied. Gravity die casting process is used to cast the ASTM tensile test specimens for analysis. In each experiment, the Ti and B contents were maintained constantly at 0.1 and 0.02 wt% respectively. The addition of yttrium was manipulated at the amount of 0, 0.1, 0.2, 0.3, 0.4 and 0.5 wt%. Microstructural characterization of the as-cast A356 alloy was investigated by means of optical microscope and its phases are detected by XRD. The mechanical properties tested are tensile strength and hardness. The inoculation of yttrium was found to enhance the grain refinement effect of Al-5Ti-1B grain refiner and improve the mechanical properties. The optimal weight percentage of yttrium was found to be 0.3. The grain refining efficiency of combining yttrium and Al-5Ti-1B on A356 aluminum alloy was mainly attributed to the heterogeneous nucleation of TiB2 and TiAl3 particles which were dispersed more evenly in the presence of yttrium and the grain growth restriction effected by the accumulation of Al-Y compound at grain boundaries.