Durmus, M.; Dispinar, D.; Gavgali, M.; Colak, M.

The most important factor affecting the production of quality parts with aluminum alloys is the quality of molten metal. One of the determining factors in molten metal quality is the minimization of trace impurity elements in the alloy. One of the most harmful impurities among these elements is Fe, and its amount is a determining factor in its negative effect. It is known that Fe negatively affects the quality of aluminum, causing a decrease in mechanical properties. Most of the Fe in the alloy forms intermetallic from needle-like to complex Chinese-script structures. In this study, carbon steel and stainless-steel rods were immersed in the liquid metal at casting temperatures of 700°C and 750°C in A356 aluminum casting alloy and were subjected to diffusion for 1, 2 and 5 hours. Subsequently, a 4-channel flow test mold with various section thicknesses was used. All samples were measured by measuring the liquid metal advance distances of all sections in mm. Then, microstructure analyses were performed on the obtained sections. As a result, it is observed that as Fe diffusion increases, liquid metal advancement distances decrease and Fe intermetallics form in the microstructure. © The Author(s) 2025. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

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

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.

AtıfScopus7·WoS6·OpenAlex7

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

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.

AtıfScopus7·WoS6·OpenAlex5

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Teke, C.; Colak, M.; Kiraz, A.; Ipek, M.

Casting simulation programs are computer programs that digitally model the casting of an alloy in the sand, shell, or permanent mold and, then, the cooling and solidification processes. However, obtaining consistent results out of casting modeling depends on the incorporation of many accurate parameters and boundary conditions. Critical Fraction of Solid (CFS), which is one of the most important of these parameters, is defined as the point where solid dendrites do not allow any flow of the liquid metal in the mushy zone. Since the CFS value varies based on many factors, inconsistent results can be experienced in the modeling applications. In this study, the CFS value obtained during the solidification of various commercial aluminum alloys' casting process, carried out using low-pressure die casting method, is predicted by using Artificial Neural Network (ANN) method based on alloy type, grain refiner and modifier additions, initial mold temperature, and pressure level parameters. In the scope of the study, 162 experiments are conducted. The results obtained from the low-pressure die casting experiments using a special model designed for the study are validated by using SOLIDCast casting simulation. The CFS values are obtained in this validation range of 33% to 61%. These CFS values are used in the development of ANN models. Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), and Mean Square Error (MSE) are used to assess the prediction accuracy of the ANN models. Calculated values of MAE, MAPE, and MSE are 0.0188, 7.06%, and 0.0006, respectively. The results show that the proposed ANN model predicts a CFS value with high accuracy.

AtıfScopus6·WoS6·OpenAlex4

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