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Öğe An application of finite element method in material selection for dental implant crowns(Walter De Gruyter Gmbh, 2021) Sensoy, Abdullah T.; Colak, Murat; Kaymaz, Irfan; Findik, FehimMaterials 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 ZrO2+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.Öğe Characterisation of aluminum alloys by octopus fluidity test(Gazi Univ, 2024) Erzi, Eray; Yuksel, Caglar; Gursoy, Ozen; Colak, Murat; Dispinar, DeryaAim 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.Öğe Characterization of properties of Vanadium, Boron and Strontium addition on HPDC of A360 alloy(Elsevier Science Sa, 2021) Gursoy, Ozen; Colak, Murat; Tur, Kazim; Dispinar, DeryaThe demand for lighter weight decreased thickness and higher strength has become the focal point in the automotive industry. In order to meet such requirements, the addition of several alloying elements has been started to be investigated. In this work, the additions of V, B, and Sr on feedability and tensile properties of A360 has been studied. A mold design that consisted of test bars has been produced. Initially, a simulation was carried out to optimize the runners, filling, and solidification parameters. Following the tests, it was found that V addition revealed the highest UTS but low elongation at fracture, while B addition exhibited visa verse. On the other hand, impact energy was higher with B additions.Öğe Determination of Acceptable Quality Limit for Casting of A356 Aluminium Alloy: Supplier's Quality Index (SQI)(Mdpi, 2019) Erzi, Eray; Gursoy, Ozen; Yuksel, Caglar; Colak, Murat; Dispinar, DeryaAluminium 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.Öğe The effect of cooling plate, mechanical vibration, and grain refinement on the microstructure and hardness of A380 produced by sand mold(Taylor & Francis Ltd, 2024) Uslu, Emin; Tigli, Ahmet; Colak, MuratThe 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.Öğe Evaluation of Fe Content on the Fluidity of A356 Aluminum Alloy by New Fluidity Index(Springer Int Publ Ag, 2024) Durmus, Melek; Dispinar, Derya; Gavgali, Mehmet; Uslu, Emin; Colak, MuratElements 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 degrees C and 750 degrees 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.Öğe The influence of metallostatic pressure, grain refiner, and modification on the critical solid fraction (CSF) of cast A380 alloy(Academic Publication Council, 2021) Colak, Murat; Dispinar, DeryaIn 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.Öğe Investigating the Optimum Model Parameters for Casting Process of A356 Alloy: A Cross-validation Using Response Surface Method and Particle Swarm Optimization(Springer Heidelberg, 2020) Sensoy, Abdullah Tahir; Colak, Murat; Kaymaz, Irfan; Dispinar, DeryaThis 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 degrees C), casting temperature (680-760 degrees 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 highestR(2)(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 degrees C, 760 degrees 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.Öğe Investigation of the Effect of Inoculant and Casting Temperature on Fluidity Properties in the Production of Spheroidal Graphite Cast Iron(Springer India, 2021) Colak, Murat; Kaya, SinanWorking 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.Öğe Investigation 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(Taylor & Francis Ltd, 2022) Colak, Murat; Arslan, IbrahimThe 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 x 10(-11) m(2)/N.Öğe Investigation of the Effects of Filling Speed, Casting Temperature and Metallurgical Quality on Fluidity of Lamellar Graphite Cast Iron at Different Section Thicknesses(Springer Int Publ Ag, 2024) Kose, Sami; Sukuroglu, Ebru Emine; Colak, MuratIn 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.Öğe MODELLING AND VALIDATION OF EFFECT OF BINDER TYPE ON FEEDING BEHAVIOUR OF SPHEROIDAL GRAPHITE CAST IRON(Taylor & Francis Ltd, 2022) Colak, Murat; Sekerden, MeteIn 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.Öğe Modification of eutectic Al-Si alloys by Sr and CuSn5(Iop Publishing Ltd, 2019) Colak, MuratEnhanced properties can be achieved in Al-Si alloys by several alloying element additions. Typical modifiers are Na, Sr, and Sb that alters Si into a fibrous structure. Fluidity and mechanical properties increase as well as machinability can be improved. In this work, eutectic Al-Si alloy was modified with Al10Sr, CuSn5, and Al10Sr + CuSn5 master alloys. Microstructural characterization was carried out by optical and scanning electron microscopy. Density and hardness of the samples were measured. Wear tests were carried out. It was found that Sr modified Al12Si revealed better performance than CuSn modified.Öğe Optimal Material Selection for Total Hip Implant: A Finite Element Case Study(Springer Heidelberg, 2019) Sensoy, Abdullah Tahir; Colak, Murat; Kaymaz, Irfan; Findik, FehimThe selection of most proper materials in engineering design is known as an important stage of the design process. In order to successfully complete this stage, it is necessary to have sufficient knowledge about the structure of materials, density, melting point, thermal expansion coefficient, tensile and yield strength, elongation, modulus of elasticity, hardness and many other properties. There are several selection systems that help the design engineer to choose most suitable material that meet the required properties. In the field of bioengineering, the selection of materials and the development of new materials for the clinical needs are increasingly important. In this study, the cases of optimal implant stabilization were investigated, material alternatives for hip prosthesis were evaluated, and optimal materials were determined. Using computerized tomography data with MIMICS software, virtual surgery was applied the hip bone and the implant was attached to bone. Boundary conditions and material properties have been defined, and finite element model has been created. FEA investigation of the mechanical behavior of the hip implant for various material alternatives determined by the CES software showed that the best material candidate is austenitic, annealed and biodurable stainless steel in terms of the micromotions at the implant-bone cement interface regarding osseointegration. This candidate showed 20.69% less strain value than the most commercially used hip implant material, Ti6Al4V. Therefore, the findings of this study suggest that the use of some specific stainless steel materials for implants may reduce the operation cost and increase the operation success for the total hip arthroplasty.Öğe Solidification analysis for variable thickness aluminum castings: simulation and chill design insights(Iop Publishing Ltd, 2023) Yilmaz, Galip; Colak, Murat; Uslu, EminManufacturing high-quality casting parts with complex geometries requires high engineering skill and precision. One essential quality concern is isolated hot spots within the castings, often in thick sections. Each hot spot must be consistently fed or mitigated through directional solidification techniques. The impact of various mold sands and the geometry of chill parts on solidification direction was investigated using specialized casting and general-purpose simulation programs. A parametric optimization method was employed to analyze directional solidification to adjust the geometry of the chill parts. The results indicate that employing diverse mold sands to enhance cooling in the thick sections was a viable strategy for achieving directional solidification in parts where the feeding pathway is obstructed due to changes in cross-section. Furthermore, the study revealed that intricate details in the chill part's geometry are not critical; however, a minimum volume (or weight) was necessary for adequate directional solidification. Lastly, an easily applicable mathematical model has been developed to determine the required volume of chill parts to ensure successful directional solidification.
