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Taguchi Approach for Optimization of Parameters that Effect Grain Size of Cast A357 Alloy

M. Çolak D. Dışpınar

Archives of Foundry Engineering | 2017 | vol. 17 | No 4 | DOI: 10.1515/afe-2017-0127

Keywords A357 Grain refinement Modification Taguchi Optimization

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Abstract

Grain refining and modification are common foundry practice for improving properties of cast Al-Si alloys. In general, these types of treatments provide better fluidity, decreased porosity, higher yield strength and ductility. However, in practice, there are still some discrepancies on the reproducibility of the results from grain refining and effect of the refiner’s additions. Several factors include the fading effect of grain refinement and modifiers, inhomogeneous dendritic structure and non-uniform eutectic modification. In this study, standard ALCAN test was used by considering Taguchi’s experimental design techniques to evaluate grain refinement and modification efficiency. The effects of five casting parameters on the grain size have been investigated for A357 casting alloy. The results showed that the addition of the grain refiner was the most effective factor on the grain size. It was found that holding time, casting temperature, alloy type and modification with Sr were less effective over grain refinement.

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Authors and Affiliations

M. Çolak

D. Dışpınar

Role of Metal Quality and Porosity Formation in Low Pressure Die Casting of A356: Experimental Observations

O. Gursoy A. Nordmak F. Syvertsen M. Colak K. Tur D. Dispinar

Archives of Foundry Engineering | 2021 | vo. 21 | No 1 | 5-10 | DOI: 10.24425/afe.2021.136071

Keywords Cast Solidification LPDC Aluminium Metal quality Bifilms Porosity

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Abstract

Porosity is one of the major problems in casting operations and there are several discussions in the literature about the porosity formation in aluminum castings. Bifilms are the defects that are introduced into the melt by turbulence. They can be detected with reduced pressure test and presented numerically by measuring bifilm index. The measure of bifilm index is the sum of total oxide length given in millimeters from the cross-section of reduced pressure test sample solidified under 0.01 MPa. In this work, low pressure die casting (LPDC) unit was built in an attempt to enhance the producibility rate. The unit consists of a pump housing that was placed inside the melt in the melting furnace where the pressure was applied instead of the whole melt surface. It was observed that the melt quality of A356 alloy was deteriorated over time which had led to higher porosity. This was attributed to the increased oxide thickness of the bifilm by the consumption of air in between the folded oxides. A relationship was found between bifilm index and pore formation.

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Bibliography

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[3] Dispinar, D. & J. Campbell, (2004). Critical assessment of reduced pressure test. Part 2: Quantification. International Journal of Cast Metals Research. 17(5), 287-294.
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[7] Aryafar, M., Raiszadeh, R., & Shalbafzadeh, A. (2010). Healing of double oxide film defects in A356 aluminium melt. Journal of materials science. 45(11), 3041-3051.
[8] Farhoodi, B., Raiszadeh, R., & Ghanaatian, M. H. (2014). Role of double oxide film defects in the formation of gas porosity in commercial purity and Sr-containing Al alloys. Journal of Materials Science & Technology. 30(2), 154-162.
[9] Amirinejhad, S., Raiszadeh, R., & Doostmohammadi, H. (2013). Study of double oxide film defect behaviour in liquid Al–Mg alloys. International Journal of Cast Metals Research. 26(6), 330-338.
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Authors and Affiliations

O. Gursoy

A. Nordmak

F. Syvertsen

M. Colak

K. Tur

D. Dispinar

e-mail: derya.dispinar@gmail.com

ORCID:

University of Padova, Italy
SINTEF, Norway
University of Bayburt, Turkey
Atilim University, Turkey
Istanbul Technical University, Turkey

Investigation of the Effect of Solidification Time and Addition Amount of Inoculation on Microstructure and Hardness in Lamellar Graphite Cast Iron

M. Çolak E. Uslu Ç. Teke F. Şafak Ö. Erol Y. Erol Y. Çoban M. Yavuz

Archives of Foundry Engineering | 2022 | vol. 22 | No 4 | 24-33 | DOI: 10.24425/afe.2022.140248

Keywords Lamellar graphite cast iron Inoculation Solidification time Modeling

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Abstract

Material suppliers typically recommend different additive amounts and applications for foundry practices. Therefore, even in the production of the same standard materials, different results may be obtained from various production processes on different foundry floors. In this study, the liquid metal prepared with the addition of different proportions of a FeSi-based inoculation, which is most commonly used in foundries in the production of a cast iron material with EN-GJL-250 lamellar graphite cast iron, was cast into sand molds prepared with a model designed to provide different solidification times. In this way, the optimization of the inoculation amounts on the casting structure for different solidification times was investigated. In addition, hardness values were determined depending on solidification time in varying amounts of inoculation additions. SolidCast casting simulation software was used to determine the casting model geometry and solidification time. In the scope of the study, sand casting, modeling, microstructure analysis, image analysis, microstructure analysis, and hardness tests techniques were used. When the results are examined, the required amount of inoculation for the optimal structure is optimized for the application procedure depending on the casting module and the solidification time.

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Authors and Affiliations

M. Çolak

e-mail:

ORCID:

E. Uslu

e-mail:

ORCID:

Ç. Teke

e-mail:

ORCID:

F. Şafak

Ö. Erol

Y. Erol

Y. Çoban

2 3

M. Yavuz

Bayburt University, Turkey
Konya Technical University, Turkey
Yavuzsan A.Ş., Turkey

Correlation Between K-value, Density Index and Bifilm Index in Determination of Liquid Al Cleanliness

A. Tigli M. Tokatli E. Uslu M. Colak D. Dispinar

Archives of Foundry Engineering | 2023 | vol. 23 | No 3 | 22-29 | DOI: 10.24425/afe.2023.144311

Keywords A206 aluminum casting K mold Liquid metal cleaning RPT Secondary aluminum

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Abstract

Aluminum alloys are widely used in the industry thanks to its many advantages such as light weight and high strength. The use of this material in the market is increasing day by day with the developing technology. Due to the high energy inputs in the primary production, the use of secondary ingots by recycling from scrap material are more advantageous. However, the liquid metal quality is quite important in the use of secondary aluminum. It is believed that the quality of recycled aluminum is low, for this purpose, many liquid metal cleaning methods and test methods are used in the industry to assess the melt cleanliness level. In this study, it is aimed to examine the liquid metal quality in castings with varying temperature using K mold. A206 alloy was used, and the test parameters were selected as: (i) at 725 °C, 750 °C and 775 °C casting temperatures, (ii) different hydrogen levels. The hydrogen level was adjusted as low, medium and high with degassing, as-cast, and upgassing of the melt, respectively. The liquid metal quality of the cast samples was examined by the K mold technique. When the results were examined, it was determined that metal K values and the number of inclusions were high at the as-cast and up-gas liquid with increasing casting temperatures. It has been understood that the K mold technique is a practical method for the determination of liquid metal quality, if there is no reduced pressure test machine available at the foundry floor.

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Authors and Affiliations

A. Tigli

1 2

e-mail:

ORCID:

M. Tokatli

E. Uslu

e-mail:

ORCID:

M. Colak

D. Dispinar

1 4

e-mail: derya.dispinar@gmail.com

ORCID:

Istanbul Technical University, Turkey
Sinop University, Turkey
Bayburt University, Turkey
Foseco, Netherlands

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Taguchi Approach for Optimization of Parameters that Effect Grain Size of Cast A357 Alloy

Abstract

Authors and Affiliations

Role of Metal Quality and Porosity Formation in Low Pressure Die Casting of A356: Experimental Observations

Abstract

Bibliography

Authors and Affiliations

Investigation of the Effect of Solidification Time and Addition Amount of Inoculation on Microstructure and Hardness in Lamellar Graphite Cast Iron

Abstract

Authors and Affiliations

Correlation Between K-value, Density Index and Bifilm Index in Determination of Liquid Al Cleanliness

Abstract

Authors and Affiliations