Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Colak, M.(3)
- Dispinar, D.(3)
- Çolak, M.(3)
- Karaali, R.(2)
- Uslu, E.(2)
- Alkan, N.(1)
- Ammas, G.(1)
- Bardakci, S.(1)
- Durmus, M.(1)
- Erol, Y.(1)
- Erol, Ö.(1)
- Gavgali, M.(1)
- Gursoy, O.(1)
- Kamiloʇlu, H.A.(1)
- Keven, A.(1)
- Kutsal, U.(1)
- Kutsal, Ü.(1)
- Nordmak, A.(1)
- Sarper, G.(1)
- Sağnak, Y.(1)
- Syvertsen, F.(1)
- Teke, Ç.(1)
- Tigli, A.(1)
- Tokatli, M.(1)
- Tur, K.(1)
- Yavuz, M.(1)
- Yilmaz, F.(1)
- Çoban, Y.(1)
- Öztürk, I.T.(1)
- Şadoʇlu, E.(1)
- Şafak, F.(1)
Yayınlar
- MakaleYayıncıda açık erişim2026Scopus SJRQ3Investigation of Fe and Mn Effects on the Fluidity Behavior of A356 Aluminum Alloys
Çolak, M.; Alkan, N.; Kutsal, Ü.
The fluidity behavior of Al–Si casting alloys is strongly influenced by impurity elements and intermetallic phase formation during solidification. In particular, iron (Fe) reduces melt fluidity by forming brittle Fe-rich intermetallics, whereas manganese (Mn) can mitigate this effect by modifying intermetallic morphology. In this study, secondary A356 aluminum alloys were produced with Fe contents of 0.10, 0.15, and 0.20 wt.% and nominal Mn additions of 0.05, 0.10, and 0.20 wt.% to investigate their combined effect on fluidity behavior. Melt quality was assessed using reduced pressure testing and density index measurements to ensure consistent casting conditions. Fluidity tests were conducted using spiral and eight-channel molds with section thicknesses ranging from 0.5 to 8 mm. To enable quantitative comparison across different section geometries, a Fluidity Index (FI) was defined based on section-normalized flow lengths. The results show that increasing Fe content generally reduces fluidity, while Mn additions significantly improve melt flow, with the most pronounced enhancement observed at 0.20 wt.% Mn. Thinner sections were found to be more sensitive to Fe-related flow restriction, whereas wider channels exhibited improved flow behavior. These findings demonstrate that appropriate Mn additions can effectively stabilize fluidity in secondary A356 alloys and provide practical guidelines for alloy control in recycled aluminum casting applications.
- MakaleAçık Erişim2026Scopus SJRQ3Optimization of Rotary Degassing Parameters to Improve Melt Cleanliness and Mechanical Properties in A356 Aluminum Alloy
Kutsal, U.; Çolak, M.; Sağnak, Y.; Bardakci, S.; Ammas, G.; Sarper, G.
Melt cleanliness is a critical factor that directly affects the quality of aluminum castings and becomes even more significant in recycling-oriented production, where high scrap utilization is inevitable. Increasing the proportion of scrap intensifies the risk of oxide films, inclusions, and gas porosity in the molten metal; therefore, efficient refining techniques are essential. In this study, the effects of rotary degassing parameters—including rotor speed, rotation time, and gas flow rate—on melt cleanliness of A356 aluminum alloy were systematically investigated. Experimental melts containing 20% primary and 80% scrap aluminum were treated under various degassing conditions using a commercial flux cleaning flux. Characterization was performed through the Reduced Pressure Test (RPT), bifilm index analysis, fluidity measurements, microstructural examinations, and mechanical testing (tensile test and Brinell hardness measurement). The results demonstrated that increasing the rotor speed from 200 rpm to 500 rpm significantly reduced both the density and bifilm indices, indicating a notable improvement in melt cleanliness. Furthermore, higher gas flow rate (10 L/min) and longer rotation time (10 min) provided additional but secondary improvements. Consequently, the optimization of rotary degassing parameters enhanced not only melt quality but also tensile strength and ductility. These findings offer practical insights for optimizing process control in recycling-based aluminum foundries.
- 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 Erişim2023Scopus SJRQ3Correlation Between K-value, Density Index and Bifilm Index in Determination of Liquid Al Cleanliness
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.
AtıfScopus7WoS6OpenAlex7
İncele - MakaleAçık Erişim2022Scopus SJRQ3Investigation of the Effect of Solidification Time and Addition Amount of Inoculation on Microstructure and Hardness in Lamellar Graphite Cast Iron
Çolak, M.; Uslu, E.; Teke, Ç.; Şafak, F.; Erol, Ö.; Erol, Y.; Çoban, Y.; Yavuz, M.
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.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2021Scopus SJRQ3Role of metal quality and porosity formation in low pressure die casting of A356: Experimental observations
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.
AtıfScopus7WoS6OpenAlex5İncele - BildiriAçık Erişim2015Scopus SJRQ3Investigation of an alternative fuel for diesel engines
Keven, A.; Karaali, R.
Internal combustion engines use generally fossil fuel products. World resources of it is limited. Renewable alternative energy sources are getting important solution for energy demand. Hazelnut oil ethyl ester is obtained from raw hazelnut and mixed with diesel oil in certain proportions to use in a four-stroke direct injected single cylinder diesel engine. In this study the effects of the mixture of diesel oil with hazelnut oil ethyl ester on the engine performance and exhaust gas emissions are investigated for the first time in literature. The fuel injection system is regulated to use the mixture in the engine for the investigation. The results show that, the mixture with 25% ethyl ester extracted from hazelnut oil can be used as an alternative fuel without any change or regulation of the diesel engine.
AtıfScopus7WoS3OpenAlex7İncele - BildiriAçık Erişim2015Scopus SJRQ3Thermoeconomic analyses of steam injected gas turbine cogeneration cycles
Karaali, R.; Öztürk, I.T.
In this study, three different gas turbine cogeneration systems that are preheating air, preheating air-fuel and simple cycles where steam injected in to combustion chamber are analyzed. The effects of steam injection on thermoeconomic performance are calculated and obtained. By using the first law of thermodynamics, the exergy analysis and economic methods, simulation programs written by the authors in FORTRAN code are obtained to use for the analyses. Thermoeconomic performance of these three different cycles for different stage and variable mass of injected steam are obtained and compared with literature. The effects of injection steam in to combustion chambers of those three cycles for variable compressing ratios, on power, efficiencies, product price and performances are obtained. Consequently, the advantages and the disadvantages of injection steam are evaluated. The results obtained in this study are compared with the results available in the literature. Injection steam into combustion chamber increases the electricity efficiency and electricity power but decreases the heat power of the cycles. Also the produced electricity price for per kWh is increasing.
AtıfScopus15WoS12OpenAlex18İncele - BildiriAçık Erişim2015Scopus SJRQ3Soil stabilization with using waste materials against freezing thawing effect
Yilmaz, F.; Kamiloʇlu, H.A.; Şadoʇlu, E.
Freezing-thawing processes hapenning in seasonally cold climate cause deformation of soil in time of freezing and strength loss while thawing. Problems of ground frost heave and soil softening belong to the important factors, that could cause serious damage and financial loss. Bayburt tuff and tuffites known as Bayburt Stone mines, located around Bayburt, play important role on economy of the Bayburt city. As a result of researches in 2005 total of 2 535 700 tons proved reserve were determined several places in Bayburt. The goal of this study is proving, that deposits of Green Bayburt Stone wastes, created in the stone quarries during the stone processing, can be used as a stabilizing material. By recycling the waste material rejected stone was mixed with lime and used as a soil stabilizator against freezing-thawing effect. Prepared natural and stabilized soil samples were subjected to freezing-thawing cycles after curing for 28 days. After the freezing-thawing cycles, compressive strength of the samples was measured to investigate the influence of the additives on the freezing-thawing properties of soil samples. As a result of this study, it was determined that samples stabilized with Green Bayburt Stone mixtures have high freezing-thawing durability as compared to unstabilized samples. As a consequence, it was seen that those mixtures can be successfully used as an additive material to enhance the freezing-thawing effects of cohessive soils.
AtıfScopus25WoS23OpenAlex28İncele - DergiActa Physica Polonica A
- DergiArchives of Foundry Engineering