Department of Metallurgical and Materials Engineering
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Item ELECTROCHEMICAL NITRIDATION OF YTTRIA STABILIZED ZIRCONIA TO PRODUCE NITRIDE CONDUCTING SOLID ELECTROLYTES(2023-01-20) ÖZTÜRK, Onur; DOĞU, DorukThe gradual increase in the world population has many effects, both positive and negative, globally. Due to the increasing population, the amount of carbon emissions per capita is also increasing. If the carbon emissions continue to increase in this way, the world average temperature will increase by 4 ℃ by 2050. With the Paris Climate Agreement, which our country has also signed, this temperature is tried to be kept at 2 ℃. Ammonia is the second most produced chemical in the world, which is used in many fields from the food sector to the energy sector. Ammonia is currently produced by a process called Haber-Bosch. This process takes place at high temperatures and pressure. As a result, it is a production method with a high energy requirement and a high amount of carbon emissions. For these reasons, scientists are looking for alternative production methods. The production of ammonia using electrochemical methods is one of the most promising alternatives. These systems enable ammonia to be produced at low-pressure values. At the same time, the fact that these systems are easily scalable is another advantage. They ensure that the ammonia production can be done onsite and on demand where it is needed, and thus offers a great energy saving. The production method using high-temperature solid oxide electrolytes is one of the most popular methods. Currently, oxide conductive electrolytes and proton conductive electrolytes are used in studies using solid oxide electrolytes. These systems aim to ionize water vapor or hydrogen, which is the source of hydrogen in both systems, and react with nitrogen. But here, due to the strong triple bond between nitrogen atoms, the ionized hydrogens recombine instead of reacting with nitrogen and turn into H2. This reduces ammonia production rate and selectivity. On the other hand, if nitride conductive electrolytes are used, nitrogen can be fed to the reaction site in ionic form reducing hydrogen recombination and increasing ammonia selectivity. Within the scope of this thesis, nitrite conductive electrolytes, which can also solve the problem in the production methods mentioned above, have been developed for the first time. First of all, the reaction system was installed and designed, then the reactor was designed with the help of Autodesk Inventor 2019. 310 stainless steel material was used in the production of the reactor. Glass seal was used as sealing material in the system and crofer mesh was used. The experiments were carried out at 550 °C. Nitrogen ion conduction experiments were carried out using 8%YSZ electrolytes (127- 140-270 µm) of different thicknesses and using an LSM-YSZ (symmetric cell) catalyst. During these experiments, a current scan was made between 0.1-300 mA and it was observed that the cell cracked at high currents. In all experiments, 15 sccm of N2 gas was fed from the cathode side and 20 sccm of He gas was fed to the anode side. The anode gas outlet is connected to the mass spectrometer gas analyzer where the signals are monitored. Nitrogen ion transfer is observed starting around 200 mA. With the data taken at different currents with 40 minutes intervals, faradaic efficiency calculations were made and the maximum efficiency was found around 40% at 300 mA current value. Electrochemical nitridation was also performed using N-Mayenite and Ce-doped LaFeO3 anode catalysts. In addition to the electrochemical nitridation study, powder nitridation studies were also carried out. Nitridation of 8% YSZ and ZrO2 powders under different temperatures, time, and flow rates in N2 rich atmosphere has been tried. In addition to these, ZrO2 powder was tried to be reduced by the carbothermic reduction method.Item EFFECT OF AUSTEMPERING ON THE MICROSTRUCTURAL AND BALLISTIC PROPERTIES OF MIL-A-12560 AND AISI 4340 STEELS(2012-10-25) DEMİRCİ, Ali Tunç; TEKİN, ErdoğanThis thesis is prepared in order to show the possibilites of the development of bainitic steel armor plates from U.S. Military Standard, MIL-A-12560 and alternatively, AISI 4340 steel to protect the civillian and military vehicles against external threats.Item INVESTIGATION OF THE HIGH TEMPERATURE OXIDATION BEHAVIOR OF CVD ALUMINIZED INCONEL 718 AND INCONEL 738LC SUPERALLOYS(2022-03-09) Telbakiroğlu, Yusuf Burak; Konca, ErkanThis study was undertaken to investigate and compare the high temperature oxidation behavior of aluminized Inconel 718 and Inconel 738LC nickel based superalloys. Bare and high activity chemical vapor deposition (CVD) aluminized Inconel 718 and Inconel 738LC samples were oxidized in air at 925, 1000 and 1050°C for 200 hours. Detailed cross-sectional examinations, elemental analyses, weight change measurements, and x-ray diffraction studies were performed in order to investigate and evaluate the oxidation mechanisms of the samples. It was observed that the oxidation resistances of both 718 and 738LC alloys were significantly improved by the protective Al2O3 layer formed on the NiAl phase that was created on the surfaces of the samples during aluminizing. The beneficial effect of aluminizing was found to be more evident in the case of 738LC alloy samples which showed lower oxidation rates at all test temperatures. It is suggested that the higher aluminum content of the 738LC alloy substrate slows down the diffusion flux of Al away from the NiAl phase and hence this is the main reason for its superior oxidation resistance.Item MECHANICAL AND BIOLOGICAL PROPERTIES OF ALUMINA AND TITANIA CO-DOPED ZIRCONIA CERAMICS(2017-01-07) Ağaç, Özlem; PARK, JongeeZirconia-based ceramics have generated considerable interests in the dental community as restorative dental materials due to their superb mechanical and chemical properties, biocompatibilty, and aesthetic characteristics. This study was to produce 3Y-TZP ceramics by adding titania and alumina as a dopant. Various amounts (ranging from 0 to 2 wt%) of TiO2 and Al2O3 were mono and co-doped to tetragonal zirconia ceramic containing 3 mol% yttria (3Y-TZP) by mechanical ball milling. The shaped samples were pressureless sintered at 1350, 1450 and 1550 °C for 2 hrs. Density, hardness, fracture toughness, and cell attachment of the co-doped 3Y-TZP ceramics were measured with respect to dopant addition. The mechanical property was determined using the method of Vickers indentation after sintering. XRD was operated to examine the crystalline phases in the titania and/or alumina-added zirconia ceramics. SEM was used for analysis of grain size and surface morphology. The results show that density decreased gradually as the amount of dopant was increased. The mechanical properties showed the maximum value when 0.5 wt% TiO2 and 1.0 wt% Al2O3 were co-doped to 3Y-TZP. Crystalline phase formation and microstructural morphology were investigated by XRD and SEM analyses to explain the variations in the properties. Co-doping of TiO2 and Al2O3 to 3Y-TZP did not have an influence on the phases present, but decreased the grain size. The co-doping also affected the cell attachment and the growth on the surface of the zirconia ceramics.Item NONDESTRUCTIVE CHARACTERIZATION OF BEARING STEELS BY MAGNETIC BARKHAUSEN NOISE TECHNIQUE(2017-06-02) Arslan, Ebru; Davut, Kemal; Şimşir, CanerOne of the most popular type of bearing steels is 100Cr6. The strength, toughness, hardness, fatigue life, wear resistance of it can be improved by heat treatment applications which also changes the microstructure. For controlling the microstructure, traditional metallographic and XRD- based methods, that involve taking representative specimens from lots, are used. Magnetic Barkhausen noise (MBN) technique may provide an alternative nondestructive, fast and practical measurement method to those traditional techniques. This study aims at investigating the possibility of nondestructive characterization of microstructure of heat treated 100Cr6 bearing steels by using the MBN technique. For that purpose, 100Cr6 steel specimens were heat treated in a quenching dilatometer under different austenitization conditions and then quenched to room temperature and to -130°C, in order to generate variations in their microstructures. After heat treatment applications, microstructural properties of the specimens including the fraction and distribution of carbides, amount of retained austenite and also hardness were determined by metallographic and XRD analysis. Moreover, MBN measurements were performed and then the results were correlated to the microstructural parameters. MBN signals correlate with the microstructure variations in the 100Cr6 steel samples via simple linear relations; however, the prediction bands were quite wide and the MBN technique was not sufficiently sensitive, for direct characterization of hardness, retained austenite and carbide fraction of the specimens that were quenched to room temperature. In order to characterize these interdependent microstructural parameters via MBN technique, non-linear relations based on carbide dissolution kinetics are needed. On the other hand, the MBN measurement results of the sub-zero treated specimens showed that; elimination of retained austenite significantly improved the goodness of fit of on those linear relations. Although coefficient of determinations of both carbide fractions and hardness were acceptable, it can be improved by developing a newer non-linear model. Nevertheless, all of the results were promising for the future applications of MBN technique on nondestructive characterization of microstructure variations in 100Cr6 steels.Item DEVELOPMENT OF NOVEL POLY(VINY ALCOHOL)/GRAPHENE NANOCOMPOSITES(2022-03-01) Gözütok, Melike; Türkoğlu Şaşmazel, HilalThe aim of this study was to develop nanocomposites by electrospinning with poly (vinyl alcohol) (PVA) and the forms of graphene, reduced graphene oxide (rGO) and Chemical Vapor Deposited (CVD)-grown monolayer graphene, in order to use them in possible applications such as packaging, electrical, thermal and tissue engineering. For this purpose, 2 major different approaches were utilized. First approach was electrospinning of PVA and rGO blend with different rGO contents (0.5 and 1 wt %), while the second approach was electrospinning of PVA solution onto a CVD grown monolayer graphene. After crosslinking of the nanocomposites, the common characterizations were done by thickness and contact angle (CA) measurements; scanning electron microscopy (SEM), mechanical property and thermogravimetric (TGA) analyses; PBS absorption and shrinkage tests, in vitro degradation and electrical conductivity measurements. Besides, chemical examinations were done via Fourier Transmission Infrared Spectroscopy (FTIR) analyses, crystallinity observations were done with X-ray Diffraction (XRD) and water vapor transmission rate (WVTR) analyses for PVA/rGO nanocomposites while optical microscopy and Raman analyses were performed for PVA electrospun CVD-grown monolayer graphene nanocomposites. The highest fiber diameter belonged to electrospun PVA+0.5 wt% rGO (~388 nm) nanocomposites whereas the lowest fiber diameter was measured for the electrospun PVA mats (~340 nm). On the other hand, the highest electrical conductivity was recorded as ~11 μS.cm-1 for electrospun PVA+1.0 wt% rGO. Additionally cell-material interactions were observed with MG-63 osteosarcoma cell-line. At the end, it was suggested that electrospun PVA+1.0 wt% rGO nanocomposites were highly suitable candidates to be used in possible applications.Item MATERIAL CHARACTERIZATION STUDIES FOR CARBURIZED QUENCHING PROCESS DESIGN AND QUALITY ASSESSMENT(2022-02-25) Yıldız, Seçil; Davut, Kemal; Şimşir, CanerCarburized quenching is a surface hardening process applied to low and medium carbon steel parts to improve fatigue and wear resistance. Distortion, cracking, inadequate case depth and surface/core hardness are the most frequently encountered problems during this process. During the last two decades, computer simulations became popular to predict and avoid those problems instead of conventional analytical and trial-and-error approaches. Aside from troubleshooting, heat treatment simulations enable determination of optimal process parameters yielding the desired microstructure and residual stress distribution to improve the performance of the part. Primary aim of this study is to complement computational materials engineering methods to develop a material data set for the carburized quenching simulation of DIN 22NiCrMo2-2 (SAE 8620H) steel. For that purpose, first, the raw material is characterized chemically and microstructurally to provide necessary input to computational techniques. Then, the kinetics of austenite growth, which has strong impact on phase transformations during succeeding quenching step, is investigated. Finally, critical temperatures and transformation kinetics are determined and presented in the form of TTT and CCT diagrams. Raw material characterization results indicate that the billets are qualified for the process and the validation study as the billets are free of macro-segregation and exhibit a homogeneous and mildly banded equiaxed ferritic/pearlitic grain structure. Moreover, austenite grain growth study revealed that the grain growth in 22NiCrMo2- 2 can be expressed by an ideal grain growth law. Finally, computationally and experimentally determined CCT diagrams are in a good agreement. The largest differences between computationally and experimentally determined TTT diagrams are observed in the bainitic transformation range which is more sensitive to hard to control factors such as local chemical composition and local prior austenite grain size. Secondary aim of this study is to conduct microstructural investigations for the quality assessment and validation of computer simulations conducted in complementary studies within the scope of the same project. In one of those complementary studies, an experimental Design of Experiments (DoE) using the Taguchi method is conducted on steel shafts made of DIN 22NiCrMo2-2 and 16MnCr5 steels to minimize the variability of the industrial process. In the other study, the same DoE is investigated using computer simulations. This thesis complements those studies with determination of microstructure and hardness distributions. The experimental results indicate an agreement with the simulations results and the agreement can be improved with better characterization of bainite transformation kinetics including its dependence on stress, local grain size and chemical composition.Item PREPARATION OF PHOTOCATALYTIC TITANIUM DIOXIDE POWDERS USING SOL-GEL PROCESS FOR WATER TREATMENT(2022-02-25) Mohammed, Ahmed Hafedh Mohammed; PARK, JongeeThis work was in an elaboration of TiO2 nanoparticles by the sol-gel process using tetra-isopropoxide as a precursor to get higher photocatalytic activity. In sol-gel method, the effects of different acids (Acetic acid, Hydrochloric acid, and Nitric acid) and different (pH) with using Hydrochloric acid as a catalyst: (pH 1.5, 2.8, 3.3 and 4) were studied. Using one of the samples synthesized, the effect of calcination temperature on the properties of synthesized TiO2 was investigated at various temperatures 450, 550, and 650 ºC. All the samples calcined at 550 ºC were characterized using XRD, SEM, and UV – Vis spectrophotometer. The titanium dioxide solution prepared by using hydrochloric acid at pH 4 was coated on a glass substrate, using dip coating technique for different cycles (1 time, 3 times, and 5 times). All coated glass of TiO2 were analyzed using UV-Vis spectrometry, UV-Vis spectrophotometer, and contact angle measurements. The results showed that only anatase phase with different crystallite size, crystallinity, and shapes of TiO2 was obtained in different kinds of acid, and the formation mechanism of TiO2 by different acid was discussed in detail. For different pH, at pH 4, 2.8, and 1.5, only the anatase type TiO2 was observed. Under acidic condition at pH 3.3, anatase and very small amount of rutile were obtained. In addition, it was shown that the crystallinity and crystallite size of anatase type TiO2 were increased when calcination temperature increased. The TiO2 powder synthesized from hydrochloric acid at pH 4 showed highest photocatalytic activity, and its photodegradation efficiency was 76.2%, 95%, and 98.1% in 30, 60, and 90 min, respectively, for methylene blue under UV irradiation. Finally, the glass coated 5 times with TiO2 sol showed superhydrophilicity and its photodegradation efficiency was 67 % in 7 h under UV irradiation.Item PRODUCTION OF API X60 AND X70 GRADE STEEL PLATES BY THERMOMECHANICAL CONTROLLED ROLLING(2022-02-22) Güneş, Seren; KONCA, ErkanThis study was undertaken as an initial work to determine the rolling and cooling conditions for the production of API PSL2 X60M and X70M grade steels plates. Two full size Nb-Ti-V microalloyed steel slabs of 200 mm thickness with compositions compliant to the API specification were sliced into 14 small size slabs and these small slabs were subjected to different thermomechanical controlled rolling and accelerated cooling operations to produce 20 mm thick plates. Specifically, the effects of i) finish rolling temperature, ii) partitioning of the total reduction between the rough and finish rolling phases, and iii) accelerated cooling using water shower were studied. Mechanical tests (tensile, impact and drop weight tear test-DWTT) and metallographic examinations of the samples taken from the trial production plates were done. The conditions that could produce fine grained ferritic microstructures with mechanical properties satisfying the API PSL 2 requirements for API X60 steel plates solely by controlled rolling were determined. On the other hand, the use of accelerated cooling in addition to controlled rolling was required for the production of API X70 grade steel plates.Item DEVELOPMENT OF A RAMAN SPECTROSCOPY SETUP(2022-02-17) Al-Izaybawee, Ammar; Durkaya, Göksel; Kurtuldu, HüseyinRaman spectroscopy is a non-destructive optical measuring technique using nonlinear light interaction with materials. It is one of the main spectroscopic techniques used to identify the molecular structure and chemical substances of a sample from their spectral signatures. In this thesis, a homemade Raman spectrometer has been constructed for studying metallurgical specimen. The system has been calibrated using standard organic samples and used for analysis of thin film coatings. Throughout the text, possible scanning design concepts were also discussed which might be employed in analysis of large samples and mapping analyses.Item DEVELOPMENT OF GRAPHENE OXIDE (GO) MODIFIED ELECTROSPUN POLY (ε-CAPROLACTONE) (PCL) NANOMATERIALS(2022-02-14) Basar, Ahmet Ozan; Türkoğlu Şaşmazel, HilalThe aim of this study was to fabricate 3D, composite tissue scaffolds with synthetic biodegradable polymer poly(ε-caprolactone) (PCL) and graphene oxide (GO) combined together by using electrospinning technique. Additionally, the effect of Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) and/or thiophene (Th) modified GO on the composite PCL/GO mats (PCL/GO, PCL/GO-GRGDSP, PCL/GO-Th, PCL/GO GRGDSP-Th) was further studied. Characterizations of the powder GO-based samples were carried out by ATR-FTIR and Raman analyses. Characterizations of the scaffolds were performed by thickness measurements, Scanning Electron Microscopy (SEM), contact angle (CA) measurements, X-ray photoelectron spectroscopy (XPS), thermogravimetric analyses (TGA), electrical conductivity tests, PBS absorption and shrinkage tests, in vitro degradation and mechanical tests. According to SEM micrographs, all of the scaffolds were exhibited bead-free and uniform morphology. Better hydrophilicity and a light CA decrease (~5°) for PCL/GO scaffolds were observed with the addition of GO. The enhanced electrical conductivity was observed with the incorporation of PCL and GO and the highest conductivity value was measured for PCL/GO-GRGDSP-Th (2%) as 15.06 μS.cm-1 . Mechanical properties of the scaffolds were improved with the well-dispersion and addition of GO in PCL matrix. Additionally, cell-material interactions were studied with MG-63 osteoblast cell line with MTT assay, ALP activitiy, Alizarin-Red staining, fluorescence and SEM analyses. Cell culture studies showed that PCL/GO GRGDSP-Th (0.5%) scaffolds exhibited highest biocompatibility performance at least 1.87 fold in MTT absorbance value compared to neat PCL scaffolds due to the advanced properties of GO and the biological interfaces.Item OPTIMIZATION OF ALLOYING AND HEAT TREATMENT PROCESS PARAMETERS OF AUSTEMPERED DUCTILE IRON (ADI) CASTINGS(2022-01-26) YALÇIN, Mustafa Alp; DAVUT, KemalAustempered ductile cast iron (ADI) has been extensively used in engineering designs since it offers a good combination of high tensile and fatigue strength, good ductility, toughness, wear resistance and damping characteristics, with light weighting and low cost. This excellent combination of properties is due to the specific microstructure of ADI; which is composed of spheroidal graphite particles on an ausferritic matrix. The ausferrite consists of carbon free acicular ferrite and carbon enriched retained austenite; which is produced via austempering heat treatment after casting. Problems such as low nodularity level or lower stability of austenite due to inadequate acicular ferrite transformation certainly deteriorate this specific microstructure and hence degrade the mechanical properties of the final product. In the present study the effect of the alloying additions of Cu and Cu + Mo + Ni, heat treatment parameters and sizes and distributions nodular graphite particles on mechanical properties and microstructure of ADI was studied. For that purpose, Y-block specimens having a lean composition and Cu, Cu + high Mo + low Ni and Cu + low Mo + high Ni alloying additions were cast. After austempering treatment, mechanical tests, fractographic and metallographic examinations were performed. The results show that the alloying additions of Cu or Cu + Mo + Ni increased carbon content and stability of austenite in the final microstructure, which means completely homogeneous ausferritic structures can be produced on larger cross-sections without the presence of pearlite or martensite. The Cu + low Mo + high Ni alloyed specimen proves that since it shows the lowest formation of martensite and has higher strength and elongation than other castings. The lean alloy on the other hand, has the highest nodularity and matrix hardness but the lowest strength and ductility because of the inadequate alloying additions, austempering time and austempering temperature. Lastly, the relation between microstructural parameters and mechanical properties were studied using the Pearson Correlation Coefficient. The results indicate a Petch like relation between grain size of austenite and yield strength, tensile strength, ductility. EBSd studies also revealed two different austenite: i) film type between acicular ferrite platelets and ii) block type around prior austenite grain (boundaries) that are not transformed during austempering. The grain size of acicular ferrite does not correlate well with the mechanical properties; since its variation among the studied samples is smaller than 0.7 m. For the studied set of samples the nodularity and size of graphite nodules are highly correlated; small differences in nodularity doesn‘t have significant effect on the mechanical properties. On the other hand smaller nodule size improves both yield and tensile strength values. In addition a Hall-Petch like relation is found between grain size of retained austenite and strength, ductility. Those results should provide a useful basis for further development and improvement of ―austempered ductile irons‖.Item PREPARATION AND CHARACTERIZATION OF INJECTABLE POLY (METHYL METHACRYLATE) (PMMA)/ZIRCONIA COMPOSITES(2022-01-25) Abdullah, Hamad Farhan; Türkoğlu Şaşmazel, Hilal; Park, JongeeThe purpose of this study is to fabricate 3D printed biomaterials. PMMA/Zirconia biomaterials were prepared by the addition of different percent weight of Zirconia powder to PMMA solution on a hot plate at 75 ˚C with continuous magnetic stirring until the stirrer stopped. The prepared sample was injected by using a syringe to get the desirable shape. Then it was sintered at different sintering temperature. Characterization of synthesized PMMA was performed by ATR-FTIR. Characterization of samples morphology were carried out by Scanning Electron Microscopy (SEM). Crystallinity and phase transformation were investigated by X-ray Diffraction (XRD). The mechanical test was performed by applying compressive strength test. According to ATR-FTIR test, synthesized PMMA showed a degree of conversion ̴ 70%. SEM micrographs showed that porosity increases with PMMA content and decreases with the increase of sintering temperature. Particles size was different, as it refers to grains agglomeration due to sintering temperature. XRD patterns showed that the percentage volume of tetragonal phase decreases with the increase of sintering temperature and crystallite size increases with the sintering temperature. Compressive strength test showed that the compressive strength increases with the increase of sintering temperature and decreases with the increase of PMMA amount.Item COATING OF TITANIUM (TiAl6V4) ALLOY BY ELECTROSPUN POLY (ε CAPROLACTONE) (PCL)(2022-01-24) Algelal, Hasan Mohammed Ali Abdullah; Şaşmazel, Hilal; Davut, KemalThe goal of this study is to fabricate a biomaterial implant composed of Titanium alloy TiAl6V4 coated with poly (ε caprolactone) (PCL) using electrospinning mechanism. Moreover, the effect of surface-treatment for the titanium alloy on the coating is also studied, whereas coating thickness is determined using a micrometer. Characterization of specimens’ morphology is executed using Scanning Electron Microscopy (SEM). The wettability of the surface is performed using the contact angle (CA) and the optical micrographs of the Titanium alloy microstructure are carried out using optical microscopy. The detection of composition and elements in the substrates Energy dispersive spectroscopy (EDS) is also performed. For more quantitative analysis of surface morphology and to evaluate the roughness at the surface of implants, AFM and roughness measurements are used. To determine the adhesion of the PCL to the TiAl6V4 , adhesion test is conducted. EDS shows that the obtained specimens are free from any other elements after being treated. The optical microscopy is used to observe the changes in the microstructure through optical micrographs, after pre-treating the alloys. Through SEM, the change in the surface morphology after grinding, polishing, and etching is also recorded. The roughness measurements indicate the mean values of roughness quantitatively, which are gradients from 0.005 micron in 3 micron polishing TiAl6V4 sample to 0.56 micron in the 120 grinding TiAl6V4 sample. After measurement, the thickness of the coating is determined as 0.01 mm. The contact angle measurement shows that the best sample in hydrophilicity is the etched alloy after coating it with PCL, which is 58.63 °. The adhesion test also proves that the best two samples for coating adhesion are the etched and 1200 grinding: more than 99% of the coating do not stick out of the coating after the removal of the tape.Item SURFACE PATTERNING OF POLY(ε-CAPROLACTONE) SCAFFOLDS BY ELECTROSPINNING FOR CELL GUIDANCE(2022-01-21) Albayrak, Deniz; Türkoğlu Şaşmazel, HilalThe aim of this work was to produce three dimentional fibrous surface patterns of Poly(ε-Caprolactone) (PCL), onto 2D smooth solvent cast PCL surfaces with electrospinning method by using a mask/stencil for cell guidance. The characterizations of produced scaffolds were done by thickness measurements, Scanning Electron Microscopy (SEM) analyses, contact angle (CA) measurements, Fourier-transform infrared spectroscopy (FTIR) and mechanical tests. According to SEM micrographs, all of the electrospun scaffold surfaces were exhibited bead-free and uniform morphology while solvent cast surfaces were smooth and nonporous. CA measurements revealed that the solvent cast surfaces had moderate hydrophilicity (~60⁰) while electrospun regions had more hydrophobic character (~110⁰ for fully electrospun surface and ~85⁰ for electrospun patterns). Mechanical testing was showed the produced scaffolds had brittle character. Also cell culture studies were performed with mouse fibroblast (L929) cells for 7 days period and cell attachment assay, MTT assay, flourescence and SEM analyses were done. Cell culture studies were indicated that the solvent cast and electrospun parts have different characteristics for cell behaviour. Thus, it is possible to achieve cell guidance for by manupulating the cell attachment and proliferation by introducing electrospun patterns onto solvent cast surfaces.