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- MakaleAçık Erişim2026Scopus SJRQ2Relationship Between Aluminum Liquid Metal Quality and Defects
Kutsal, Umit; Colak, Murat; Ertugrul, Onur
Aluminum alloys are commonly used in various industries today. In order to produce defect-free high-quality alloys with sustainable processes, defects must be reduced, and liquid metal quality must be improved. There are various methods that can be used for the measurement of liquid metal quality. Some of which are density index, bifilm index, K-Mold index, PoDFA, Prefil, fluidity test, and thermal analysis. The relationship and validation between these methods are still not clear. In this study, the relationship between aluminum liquid metal quality and defects is analyzed. Three different conditions were utilized. These conditions are (1) before a controlled degassing, (2) after the controlled degassing and (3) after the liquid metal is transferred to the holding furnace. According to the results, it was observed that the reduction of bifilms index did not reduce other inclusions and did not always favorably affect other measurement methods. It was also observed that the reduction of bifilm index did not improve the porosity level. Moreover, it was found that elongation values are related to the largest defect diameters. Bifilm index are not the only factor affecting the elongation and the density index directly affects the defect distribution. K-Mold index has an impact as it shows macro-inclusions. However, bifilm index, density index, fluidity index and K-Mold index are not as sufficient as numerical calculation of defect size by computed tomography (CT). The main factor directly affecting the elongation and tensile strength was found to be the inclusion size and diameter in the CT result. Examination of the fracture surfaces revealed that oxide contents are present, and the oxygen orientations and aluminum orientations are compatible. This harmony is thought to be related to the orientation of the bifilms in the structure.
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İncele - MakaleAçık Erişim2025Scopus SJRQ2Microstructure and Mechanical Properties Change of Al7SiMgxEr (x: 0.03–0.1)
Colak, Murat; Muhammed, Enes Aydin; Turkmen, Mustafa; Dispinar, Derya
Aluminum and its alloys are widely used in many fields, such as automotive, aerospace, and defense industries, due to their many advantages. Due to such critical applications, the quality demands are also increasing. With the recent development in technologies, studies on casting of aluminum with different alloying element additions are ongoing rapidly. Various elements are added to the alloy to provide the desired properties. In this study, the effects of 0.03, 0.06, and 0.1 wt% Er addition to A356 aluminum alloy were evaluated simply because in the literature, only 0.1 wt% and above additions were studied. Samples were prepared using permanent molds and subjected to mechanical testing and microstructural characterization. Changes in the microstructure (evaluated via SDAS and SDAL) and mechanical properties of the cast specimens were analyzed. The results showed that Er addition improved tensile strength by up to 30%, increased elongation fourfold, and enhanced toughness by a factor of 4.5.
- MakaleAçık Erişim2025Scopus SJRQ3Effect of Fe Amount on Microstructure and Fluidity of A356 Alloy
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.
- MakaleAçık Erişim2025Scopus SJRQ2Evaluation of Fe Content on the Fluidity of A356 Aluminum Alloy by New Fluidity Index
Durmuş, Melek; Dispinar, Derya; Gavgali, Mehmet; Uslu, Emin; Çolak, Murat
Elements that are deliberately added to aluminum alloys or are incorporated into the alloy later depending on the production process affect the final product properties. In addition, liquid metal cleaning is important in minimizing undesirable elements. Considering the production process, one of the most harmful impurities that is likely to pass into the alloy via diffusion for aluminum is the element, Fe. It is known that this is due to the fact that although Fe is highly soluble in liquid aluminum and its alloys, it has very little solubility in solids. Depending on the Fe content, mechanical properties, porosity and fluidity properties are affected in aluminum alloys. In this study, stainless and carbon steel rods were dipped into the melt at 700 °C and 750 °C for 1, 2 and 5 h. Castings were performed before and after degassing. Four-channel fluidity mold with different section thickness was used in the trials. Additionally, microstructure characterization was performed under varying casting conditions. Fluidity Index was proposed which is a single value measured from all fluidity values in different sections. When the results were examined, it was determined that the diffusion material, holding time, casting temperature and liquid metal cleanliness had an effect on the fluidity. Due to the increase in diffusion time, a decrease in fluidity was observed in both carbon steel and stainless steel. It was found that fluidity was significantly reduced when using stainless steel.
AtıfScopus14WoS14OpenAlex15İncele - MakaleAçık Erişim2025Scopus SJRQ2Investigation of the Effect of Vanadium Addition on Mechanical Properties in A356 Aluminum Casting Alloys
Çeker, Merve; Çolak, Murat
The superior properties of aluminum alloys are further improved by the addition of different elements and gain new qualities. In the aluminum casting industry, vanadium (V) addition plays an important role to improve the mechanical and physical properties of these alloys. In this study, different amounts of V (0.03%, 0.06% and 0.1%) were added to A356 alloy, and its effects on mechanical properties and microstructure were investigated experimentally. The liquid metal degassing process was applied in all experiments in order not to affect the results of gases and inclusions in the liquid metal before casting. In the study, degassing was assessed by the Reduced Pressure Test (RPT). Tensile and hardness test specimens were performed with specimens obtained from mechanical test molds. When the results were examined, the elongation amount, which was 2.7% in A356 casting without addition, increased with the addition of V and reached a maximum value of 7.6% with 0.1% V addition. Tensile stress values were 137 MPa in A356 castings without addition, 159 MPa with 0.03% V addition, 168 MPa with 0.06% V addition and increased up to 185 MPa with 0.1% V addition.
AtıfScopus5WoS5OpenAlex5İncele - MakaleAçık Erişim2019Scopus SJRQ2Determination of acceptable quality limit for casting of a356 aluminium alloy: Supplier’s quality index (SQI)
Erzi, Eray; Gürsoy, Özen; Yüksel, Çağlar; Colak, Murat; Dispinar, Derya
Aluminium and its alloys have been widely used in the automotive industry for some time and A356 is one of the most popular aluminium alloys today in the sector. It contains approximately 7 wt.% Si and 0.3 wt.% Mg. Due to the defects that may be present in the cast parts, expected mechanical properties may not be reached and this alloy may perform in service under its potential. In a low pressure die casting, several precautions have to be taken in order to produce high quality and defect-free castings. Temperature of casting and the schemical composition of the melt is recorded continuously. Die temperature, pressure levels and their durations are optimized; degassing and fluxing operations are performed. Yet, regardless of the precautions, there could still be rejected parts. It is becoming clear that a good quality raw material is one of the most underrated points of the industry and that the starting material has a great effect on the final product and it should be taken in to account more seriously. Therefore, regarding the first rule of Campbell’s 10 Rules of Casting, in this study, the quality of the starting material of supply chains for a wheel manufacturer was investigated. Chemical compositions were compared, fluidity tests, mechanical tests and bifilm indexes of these various sources and ingots were measured and a final quality index was proposed to create a reference for the quantification of quality of supplier’s ingots. This new index was compared with the rejection rates.
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