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- MakaleAçık Erişim2026Scopus SJRQ2Investigation of the Effect of Niobium Addition on Fluidity and Mechanical Properties in Casting of Aluminum Alloys
Çolak, Murat; Yalçin, Önder
Aluminum and its alloys are important engineering materials widely used in the defense industry, industrial production, and machinery industry. Depending on the increase in quality expectations from aluminum casting alloys, castings are made with different alloy element additions. In the study, the effects of Nb addition to A356 aluminum alloy on casting properties were investigated with experimental studies. The Nb addition rate in the alloy was determined as 0.03%, 0.06% and 0.1%. Four-channel fluidity mold with varying section thicknesses, spiral fluidity mold and mechanical test mold were used in casting experiments. As a result, with the addition of Niobium, an increase in maximum tensile strength and % elongation was observed, while a decrease in fluidity properties was observed.
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İncele - MakaleAçık Erişim2026Scopus SJRQ2Bioinspired Sternal Implant Design for Generic Anatomical Reconstruction: An In Silico Framework for Material Selection and Biomechanical Validation
Kutbay, Işıl; Gerdan, Zeynep; Çolak, Murat; Tabak, Yasemin; Şensoy, Abdullah Tahir
The sternum protects the intrathoracic organs and contributes to chest wall mechanics, which makes reconstruction after tumor resection, trauma, or infection a demanding biomechanical problem. This study presents an in silico workflow for preselecting materials for sternal implants before physical prototyping. After a virtual resection, an anatomically conformal implant was designed and candidate biomaterials were screened in CES Selector using density, elastic modulus, fatigue strength, fracture toughness, toxicity, medical grade suitability, and MRI safety. A representative subset of the screened candidates was then compared by finite element modeling in terms of stress transfer and deformation. Seventeen candidates met the screening criteria. Ti-13Nb-13Zr showed an elastic modulus of about 80 GPa, and the titanium-based candidates showed deformation values of about 0.96 to 1.03 mm, whereas GF PEEK reached about 1.74 mm. The stress shielding index also showed that titanium-based materials remained on the implant-dominant side, while polymer-based materials shifted stress transfer toward bone. Taken together, the findings suggest that Ti-13Nb-13Zr offers the best overall balance for load-bearing sternal reconstruction, whereas PEEK-based systems may be more suitable within the present model for hybrid or adjunct designs. The proposed workflow can support early implant planning and guide future experimental and clinical studies.
- MakaleYalnız künye2026Scopus SJRQ2Effect of Erbium Addition to A380 Aluminum Alloy on Mechanical and Microstructural Properties
Gültekin, Çağrı; Çolak, Murat; Tabak, Yasemin; Şensoy, Abdullah Tahir
There are many studies on improving the properties of aluminum alloys, but the addition of rare earth elements occupies a particularly important place among them. In this study, the effect of erbium (Er) addition on the microstructure and mechanical properties of A380 aluminum casting alloy was systematically investigated. A series of alloys with varying Er contents (0.03%, 0.05% and 0.1 wt.%) was fabricated using the conventional casting method. The addition of Er led to significant grain refinement, primarily due to the formation of Al3Er intermetallic particles, which acted as potent nucleation sites during solidification. Optical microscopy and SEM analyses confirmed the morphological transformation of the eutectic silicon phase into a finer and more fibrous structure. Mechanical testing revealed that the alloy containing 0.1 wt.% Er exhibited the highest ultimate tensile strength (236 MPa), elongation (4.56%), and hardness (87.6 HB), indicating an optimal balance between strength and ductility. The improvement is attributed to both microstructural refinement and dispersion strengthening mechanisms. These results suggest that controlled Er addition can be an effective strategy for enhancing the performance of cast Al–Si alloys, making them promising candidates for demanding structural applications in the automotive and aerospace industries.
AtıfScopus3WoS1İncele - MakaleAçık Erişim2026Scopus SJRQ2Microstructural Evolution of Vanadium-Modified A380 Aluminum Alloy under Different Solidification Conditions
Çolak, Murat; Avci, Ömer; Demir, Muhammet Emin
Quality requirements for aluminum alloys are continuously increasing with technological advancements, driving the need for improved alloy design and casting control. Alloying additions and solidification conditions play a decisive role in determining the microstructural characteristics of cast aluminum alloys. In this study, a commercial A380 aluminum alloy was modified with vanadium (V) additions of 0.03, 0.06, and 0.1 wt.% and cast in step permanent molds with section thicknesses ranging from 5 to 30 mm, enabling a systematic investigation of different solidification conditions. Melting, liquid metal treatment, metallographic preparation, SEM/EDS analysis, density measurements, and solidification modeling were employed. The results demonstrate that vanadium addition and solidification time jointly govern the morphology and distribution of eutectic silicon and intermetallic phases. Under the investigated casting conditions, a V addition of 0.06 wt.% resulted in the most homogeneous microstructure, while higher V content led to the formation of coarser intermetallic phases, particularly at longer solidification times. These findings emphasize the importance of considering the combined effects of alloying and solidification parameters when optimizing the microstructure of A380 aluminum castings for industrial applications.
- MakaleAçık Erişim2026Scopus SJRQ2Experimental and Modeling Study of Fluidity in Ductile Iron (GGG40)
Coşar, Mehmet; Şüküroğlu, Ebru Emine; Güngör, Kadir; Çolak, Murat
Ductile irons (spheroidal graphite cast irons, SGI) are widely used in automotive and energy systems due to their high strength, ductility, and excellent machinability. The casting quality of these alloys largely depends on the flow and filling behavior of the molten metal, namely its fluidity. In this study, the effects of pouring temperature, filling time, and metallurgical quality on the fluidity of GGG40 ductile iron were investigated through both experimental and numerical approaches. Experimental trials were conducted at pouring temperatures of 1350 °C, 1400 °C, and 1450 °C; metallurgical quality levels of 10%, 50%, and 90%; and filling times of 5 s and 10 s. The fluidity lengths were measured and statistically evaluated. The results revealed that increasing the pouring temperature and metallurgical quality significantly improved fluidity, while shorter filling times allowed the molten metal to travel longer distances before solidification. Modeling studies performed using a commercial casting simulation software showed strong correlation with the experimental data. Microstructural examinations indicated that higher pouring temperatures and improved metallurgical quality led to a more homogeneous distribution of graphite nodules and an increased ferrite fraction in the matrix. The findings provide valuable insights into the influence of process parameters on the fluidity behavior of ductile iron and offer critical design data for enhancing casting quality and productivity in industrial foundry applications.
AtıfScopus1İncele - MakaleYalnız künye2026Scopus SJRQ2Effect of Scandium Addition on Recycled A356 Alloy: Experimental Investigation and CALPHAD-Based Thermodynamic Analysis
Kutsal, Ümit; Barutçuoğlu, Burak; Sağnak, Yiğit; Toker, Abidin; Çatar, Recep; Çolak, Murat
This study systematically investigates the influence of scandium (Sc) additions at 0.1, 0.2, and 0.3 wt.% on the melt quality, microstructural characteristics, fluidity, and mechanical performance of A356 aluminum alloy under recycling-oriented casting conditions. The alloy charge consisted of 20% primary aluminum and 80% recycled scrap, while the Fe content was maintained at 0.2 wt.%. Melt treatment was performed by rotary degassing using a commercial flux. Melt quality was assessed using the Reduced Pressure Test (RPT) and bifilm index analysis, whereas casting performance was evaluated through an eight-channel fluidity test. Mechanical behavior was characterized by tensile and Brinell hardness testing, and microstructural and phase analyses were conducted using scanning electron microscopy (SEM) and X-ray diffraction (XRD). To complement the experimental investigation and provide a thermodynamic basis for interpretation, phase stability, solidification behavior, and phase-fraction evolution were examined using Thermo-Calc within the CALPHAD framework. By combining experimental characterization with computational thermodynamic analysis, this study elucidates the effect of Sc content on the processing–microstructure–property relationships of recycled A356 alloys and provides a systematic basis for evaluating Sc modification in high-recycled-content aluminum castings.
- MakaleAçık Erişim2025EFFECT OF SCRAP RATIO ON LIQUID METAL QUALITY OF LOW-PRESSURE DIE-CASTING (LPDC) ALLOY USING ROTARY DEGASSING
Tokatli, Mehmet; Çolak, Murat; Yüksel, Caglar
Although various processes are used in aluminum liquid metal cleaning, environmentally friendly, economical and applicable methods should be preferred in industry. Among these methods, the Density Index test based on the reduced pressure test (RPT), which is widely used to measure the efficiency of the rotary degassing process, and the K-mold test method, which offers fast and practical results were carried out. The effects of rotary degassing method on the liquid metal quality of AlSi7Mg0.3 (A356) aluminum alloy charges prepared with different proportions of scrap and ingots were evaluated using a constant 5l/min gas flow rate, a constant 5 min process time and a constant 300 rpm rotor rotation speed. The results show that the Density Index values can be reduced from 1.48% to around 0.74% with increasing scrap rate, while K-mold values can be reduced from 2.8 to 0.6. It was also shown that the rotary degassing method is effective in liquid metal cleaning, and the K-mold test can be used as a very practical control tool for evaluating liquid metal quality.
- MakaleAçık Erişim2025Scopus SJRQ2Importance of Melt Cleaning Parameters on Reliability of Tensile Properties in A356 Alloy
Tigli, Ahmet; Uslu, Emin; Çolak, Murat; Dispinar, Derya
This study examines how melt treatment and pouring temperature affect the microstructure and mechanical properties of A356 aluminum alloy. Samples were cast under degassed, non-degassed, and upgassed conditions at 725, 750, and 775 °C. Melt quality was assessed using the reduced pressure test (RPT) and the bifilm index (BI), while microstructural features were analyzed via SEM and EDS. Tensile testing and Weibull statistics were used to evaluate mechanical performance and variability. Results showed that by improper degassing the reproducibility of mechanical properties decreased regardless of hydrogen content of the melt. When bifilm index (BI) was high (> 50 mm), the ductility was lowered and caused greater variability in strength and elongation. SEM confirmed large oxide films in samples, linked to the brittle fracture. The work also highlighted the importance of melt cleaning parameters for the reliability of cast aluminum alloys regardless of the hydrogen content.
AtıfScopus3WoS3OpenAlex3İncele - 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 Effects of Filling Speed, Casting Temperature and Metallurgical Quality on Fluidity of Lamellar Graphite Cast Iron at Different Section Thicknesses
Köse, Sami; Çolak, Murat; Şüküroğlu, Ebru Emine
In this study, the fluidity properties of the alloy were investigated at different casting temperatures, different section thicknesses, and varying casting parameters of lamellar graphite cast iron materials. To achieve our goal, we utilized sand molds that were created with specific parameters including pouring temperature, metallurgical quality, section thickness, and fluidity test model. These molds were used for casting. Thus, the effect of fluidity properties in changing casting conditions and liquid metal advance distances at determined section thicknesses was investigated. Modeling was carried out with FlowCast casting simulation software by determining the liquid metal advance distance depending on the section thickness in the castings made in sand molds under changing casting conditions. The fluidity and advance distance of the liquid metal was determined comparatively with experimental and modeling techniques under the changing casting conditions in the parameters determined in this study. When the outcomes were examined; it was observed that different liquid metal advance distances occur at different cross-section thicknesses depending on the changing conditions.
AtıfScopus8WoS8OpenAlex7İncele - 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 Erişim2024Characterisation of aluminum alloys by octopus fluidity test
Erzi, Eray; Yüksel, Caglar; Gürsoy, Ozen; Çolak, Murat; Dispinar, Derya
Aim Determination of fluidity and tensile property characteristics of A206, A201 and A380 alloy with new octopus design Design & Methodology Melting and casting of alloys into sand moulds. Measurement of fluidity length and tensile properties Originality New fluidity test mould design where different cross section thicknesses are used to characterise the alloy properties Findings A356 has the lowest fluidity. A201 has lower fluidity compare to A206 but has the highest strength. A380 has similar characteristics with A201 Conclusion A380 can be an alternative choise for A201 alloy Declaration of Ethical Standards The authors of this article declare that the materials and methods used in this study do not require ethical committee permission and/or legal-special permission.
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İncele - MakaleAçık Erişim2024Scopus SJRQ3The effect of cooling plate, mechanical vibration, and grain refinement on the microstructure and hardness of A380 produced by sand mold
Uslu, Emin; Tiğli, Ahmet; Çolak, Murat
The mechanical properties of aluminium alloys can be increased by controlling the grain size and morphology of the alloy. In these studies, mechanical vibration, cooling slope plate (CSP), and grain refiner were applied on sand mould casting using A380 alloys. The hardness, and microstructure of the cast samples are investigated. These processes lead to the refinement of grain structures and a decrease in the tendency for dendritic structure formation. The Effect of the solidification time (modulus) on the microstructure is investigated. It was determined that the solidification time varies depending on the section thickness, which affects the SDAS values. It was observed that the lowest SDAS values were in CSP and the highest values were in grain refiners added casting. The lowest hardness value was recorded at CSP casting. Meanwhile, the grain refiner added vibration casting exhibits the highest hardness.
AtıfScopus10WoS10OpenAlex10İncele - MakaleAçık Erişim2024Scopus SJRQ2Exploring alternative polymer materials for joint liners: a software-guided material selection
Yilmaz, Galip; Gerdan, Zeynep; Çolak, Murat
This study explores the alternative polymer materials and selection process for joint implant liners, focusing on applying CES Selector software to identify suitable polymer materials. CES Selector provides an easy-to-use interface. It offers multiple selection methods, including boundary values and property constraints. Seven materials were excluded from the analysis, resulting in 19 potential candidates, including unconventional options like EVOH, PCTA, PESU, PI, PPA, PPC, PPSU, and PSU. The materials underwent evaluation based on key criteria, including tensile strength, Young’s modulus, compressive strength, fatigue strength, and fracture toughness. Overall, TPU exhibited a remarkable combination of high mechanical strength and adaptable Young’s modulus, making it a top contender. However, in other evaluation criteria, PI surpassed TPU, solidifying its potential as a superior choice. This systematic approach provides valuable insights for engineers and designers seeking innovative materials for joint implant liners. The study results broaden the range of materials used in implant manufacturing, providing potential alternatives that offer better long-term durability and performance.
- MakaleYalnız künye2022Scopus SJRQ2Investigation of the effect of the addition of grain refiner and modifier addition on wear properties in sand and permanent mould casting of A357 and A380 aluminium alloys
Çolak, Murat; Arslan, İbrahim
The aim of this study is to improve the tribological behaviour of aluminium alloys by using grain refiner and modifier. The effects of Al5Ti1B grain refiner and Al10Sr modifier additives on friction and wear properties on A380, A357 alloys produced by pouring sand andpermanent mould casting were investigated. Abrasion tests were carried out under dry conditions against St1040 steel disc using a pin-disk system with 20 N load and 1.0 m/s sliding speed. It was determined that grain refiner and modifier additives decrease the friction coefficient and increase the wear resistance. It was determined that the samples produced by permanent mould casting method decreased the friction resistance by 9% and the abrasion resistance increased by 40% compared to the samples produced in sand mould. The lowest wear rate was obtained in A380 alloy with TiB and Sr added with a value of 4.87 × 10–11 m2/N.
AtıfScopus12WoS10OpenAlex13İncele - MakaleYalnız künye2022Scopus SJRQ2MODELLING AND VALIDATION OF EFFECT OF BINDER TYPE ON FEEDING BEHAVIOUR OF SPHEROIDAL GRAPHITE CAST IRON
Çolak, Murat; Şekerden, Mete
In the casting method, it is crucial to properly make the moulding design to produce sound parts. Volumetric change, especially during the solidification of spheroidal graphite cast irons, may show different behaviour compared to steel and aluminium castings. In this study, castings were carried out with single and double feeders with varying casting parameters of green sand and resin mould sand containing different cross-sectional thicknesses. Depending on the chemical composition, mould rigidity and inoculation efficiency, and the importance of the feeder path was evaluated by experimental and modelling techniques. Consequently, it was observed that the risk of shrinkage in resin moulds is less than in green sand castings in the same moulding design. In addition, it has been found that the number of feeders and neck connection is an important parameter in pore formation.
AtıfScopus2OpenAlex3İncele - Derleme MakaleAçık Erişim2021Scopus SJRQ2Investigation of the Effect of Inoculant and Casting Temperature on Fluidity Properties in the Production of Spheroidal Graphite Cast Iron
Çolak, Murat; Kaya, Sinan
Working with liquid metal makes the casting method very advantageous, but also presents some difficulties. One of the common challenges in the casting process is that the liquid metal may not fill the mold cavity completely. This is mainly due to the contact of the liquid metal with the mold surface in the mold cavity, the high heat transfer coefficient of the mold material, and the undercooling and solidification of the liquid metal during liquid movements. For this reason, the fluidity of the liquid metal is important for robust casting production. The fluidity is affected by many factors such as mold properties, casting temperature, and alloying elements. In this study, it is aimed to investigate the fluidity characteristics of GGG60 alloy. For this purpose, the effects of casting temperature, different inoculants, and different inoculant quantities were used in the new mold design, which has different cross-sectional thicknesses. The distance of the alloy in the cavities was also compared with FlowCast Casting simulation software.
AtıfScopus8WoS8OpenAlex9İncele - MakaleAçık Erişim2021Scopus SJRQ3The influence of metallostatic pressure, grain refiner, and modification on the critical solid fraction (CSF) of cast A380 alloy
Çolak, Murat; Dispinar, Derya
In this work, porosity formation with regard to the change in the metallostatic pressure was investigated. Different geometry was generated to simulate the effect of pressure on critical solid fraction. A380 alloy was sand cast. Additionally, the effect of grain refiner and modifiers was also investigated. Samples were subjected to X-ray radiography and density measurement to quantify the pore size and distribution.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2021Scopus SJRQ3An application of finite element method in material selection for dental implant crowns
Sensoy, Abdullah T.; Çolak, Murat; Kaymaz, Irfan; Findik, Fehim
Materials used for dental crowns show a wide range of variety, and a dentist's choice can depend on several factors such as patient desires, esthetics, tooth factors, etc. One of the most important issues for implant surgery is the primary stability and it should be provided to minimize the risks of screw loosening, failed osseointegration, or nonunion. The current study aims to present the Finite Element Analysis (FEA)-based material selection strategy for a dental crown in terms of reducing the aforementioned risks of dental implants. A virtual surgery mandible model obtained using MIMICS software was transferred to the ANSYS and material candidates determined using CES software were compared using FEA. The results indicated that Zr02+Y2O3 (zirconia) has shown a 12.79% worse performance compared to Au83-88/Pt4-12/Pd4.5-6 alloy in terms of abutment loosening. On the other hand, zirconia is the most promising material for dental crowns in terms of the stability of the bone-implant complex. Therefore, it may show the best overall performance for clinical use. Moreover, as suggested in this study, a better outcome and more accurate predictions can be achieved using a patient-specific FEA approach for the material selection process.
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İncele - MakaleYalnız künye2020Scopus SJRQ2Investigating the Optimum Model Parameters for Casting Process of A356 Alloy: A Cross-validation Using Response Surface Method and Particle Swarm Optimization
Şensoy, Abdullah Tahir; Çolak, Murat; Kaymaz, Irfan; Dispinar, Derya
This study aimed to determine the optimal casting parameters for the maximum fluidity of A356 alloy. Gravity die cast method was used. For this purpose, central composite design (CCD) was performed. The input parameters and their limits for the trial design were selected as pre-heating temperature (100–400 °C), casting temperature (680–760 °C), and cross-sectional thickness (1–10 mm). Using the CCD-based simulation results of the feed distance, a highly correlated full-quadratic regression equation was obtained with the highest R2 (0.99), which then was used as the objective function for the particle swarm optimization (PSO) process. The highest value of the response parameter, flow distance, reached up to 491.19 mm when the input parameters were selected as 400 °C, 760 °C and 10 mm, respectively. The sensitivity analysis has shown that the most effective parameter on the fluidity is the cross-sectional thickness. The response surface method (RSM)-based optimization results have been also validated using the PSO method. Although the higher temperatures have been found to result in better fluidity, there may be some drawbacks to working at higher temperatures such as energy cost and mould life. To determine the optimum input parameters, the RSM model suggested in this study can be modified for any type of casting process. Moreover, especially for a complex-shaped part, the manufacturer can be advised regarding operating conditions such as pre-heating and casting temperatures.
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