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Öğe Application of Digital Image Correlation technique to Erichsen Cupping Test(Elsevier - Division Reed Elsevier India Pvt Ltd, 2018) Aydin, Murat; Wu, Xin; Cetinkaya, Kerim; Yasar, Mustafa; Kadi, IbrahimDigital Image Correlation (DIC) technique is a powerful and useful tool in many industrial applications for both scientific and commercial purposes. It has been widely used for mechanical tests to understand the behaviour of material. In this study, 3D DIC technique was adopted to Erichsen Cupping Test (ECT) to measure the fracture cup height and demonstrate its benefits over traditional measurement techniques. Ck75 steel sheet with various material thickness was used in the experiments. The flat specimens were fixed in a closed die set-up and stretched along two directions until fracture. All the experiments were performed on a manually operated hydraulic press with a constant cross-head displacement and recorded with high resolution cameras. Finally, to determine the fractured cup heights, the accurate and satisfactory results were obtained through DIC measurements. The full-field thickness distribution and the maximum fracture forces were also determined. (C) 2018 Karabuk University. Publishing services by Elsevier B.V.Öğe The effect of aging heat treatment on the sliding wear behaviour of Cu-Al-Fe alloys(Elsevier Sci Ltd, 2009) Yasar, Mustafa; Altunpak, YahyaAluminium bronze is one of the versatile wear resisting engineering materials that work under a corrosive environment with high stress. Alloys were produced by casting of C95200 and C95300 aluminium bronzes and aged. Wear behaviors, friction coefficient, and microstructure were investigated. The results indicated that a suitable aging treatment resulted in the formation of smaller alpha grains than their cast condition. These small alpha grains could improve the hardness and wear resistance of Cu-Al-Fe alloys. But with increasing aging temperature, the wear rate of the aged Cu-Al-Fe alloys initially decreased and then began to increase. (C) 2008 Elsevier Ltd. All rights reserved.Öğe Effect of Changing of Filling Materials in NR-SBR Type Elastomer Based Rubber Materials on Mechanical Properties(Polymer Soc Korea, 2014) Bulbul, Saban; Yasar, Mustafa; Akcakale, NuretttinThe effects of different filling materials and stabilizers in polymer based materials that are used as shoe soles in the shoemaking industry on the mechanical properties (strength, failure, tensile, tearing, bending etc.) of the final products have been examined in this study. Natural rubber (NR RSS3) and styrene-butadiene rubber (SBR 1502) were used as the main matrix material. New compounds were formed by replacing the fillings in the general compound of the existing factory (SiO2, CaCO3) with 40% (1200 g) blast furnace flue dust, rice husk, reclaimed rubber (recycled) and wood ash. Comparison of the new compounds with the existing compounds revealed a decrease in hardness, density, dimension stability, bending, tearing, % elongation and failure strength and an increase in wearing.Öğe THE EFFECT OF WOOD ASH ON THE MECHANICAL PROPERTIES OF RUBBER COMPOUNDS(Inst Za Kovinske Materiale I In Tehnologie, 2019) Bulbul, Saban; Akcakale, Nurettin; Yasar, Mustafa; Gokmese, HakanIn this study, the effect of adding wood ash (oak tree) on the mechanical properties (tensile, abrasion, tearing, elongation %, etc.) of NR/SBR-type elastomer materials was investigated. Five different compounds were prepared by adding 16 %, 32 %, 48 % and 64 % wood ash to the filler and additive materials in the general composition (G). The mechanical test results and production costs of the new compounds composed were compared between themselves and with the G compound. The fracture surfaces of the compounds as well as the shape and morphological distribution of the fillers in the rubber matrix were examined using a Scanning Electron Microscope (SEM). As a result of the experimental studies, it was found that the new compounds composed had an increased tensile and tearing strength. abrasion amounts, bending capability, unit elongation amounts and densities in comparison to the G compound. A decrease was observed in the hardness values and material costs (production cost) of the compounds.Öğe Effects of Die Corner Radius and Temperature on the Formability of AA7075-T6 Alloy(Chinese Acad Sciences, Inst Metal Research, 2013) Evlen, Hatice; Kadi, Ibrahim; Yasar, MustafaThis study focused on the formability of aluminium alloy (7075-T6) sheets through hydroforming route. Formability of these sheets was tested using a warm forming setup at three different temperatures and four different die corner radii. Forming limit diagrams (FLD) were generated by measuring the grids of the sheet formed. The results show that the forming limit of AA7075-T6 can be significantly improved when the blank was heated to 140-250 degrees C. It was also observed that as the temperature increases above 140 degrees C, dome height began to decrease. Also the results indicated that both the die corner radius and temperature have a significant effect on the stress-strain curve and warm forming of AA7075-T6 sheets. Thus, with the temperature increased from room temperature (RT) to 140 degrees C, the flow stress decreased and the strain increased, hence, the formability is enhanced. However, further increase in temperature causes decreases the flow stress and strain. Similar changes of the flow curve were seen in die corner radius. Decreasing the die corner radius decreases the flow stress and increase the strain. Moreover, an equation was obtained by establishing correlations between the experimental parameters and their results. In this way, it became possible to make predictions.Öğe Examination of tribological behaviours of aged Cu-Be alloys(Natl Acad Sciences Ukraine, Inst Metal Physics, 2007) Yildiz, H. Burak; Yasar, MustafaIn this examination, characteristics of wear of Cu-Be alloys are studied after application of thermal treatment of ageing to Cu-Be alloys. Cu-Be alloys were taken into solution at 820 degrees C before process of ageing and allowed for 30 min at this temperature. After fast cooling, they were aged at 400-450-500-550 degrees C for 120 min. Characteristics of a microstructure of Cu-Be alloys were determined according to analysis by a scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS) of these alloys, which have undergone to thermal treatment of ageing, but not to process of ageing. Cu-Be alloys aged at various temperatures were then corroded using pin-on-disc wear device, and thereby their characteristics of wear were examined. In wear tests, four different loads including 20-30-40-50 N and four different distances of slip including 250-500-1000-2000 m were used. As a result of such tests, it has been determined that the wear resistance of Cu-Be alloys has decreased rapidly with increase of wearing force. It was also observed that wearing losses were increased linearly depending on a distance. Worn quantities of the materials subjected to treatment of ageing especially at temperatures above 450 degrees C were increased rapidly during ageing.Öğe FABRICATION OF OPEN-PORE BIODEGRADABLE MAGNESIUM ALLOY SCAFFOLD VIA INFILTRATION TECHNIQUE(Springer Int Publ Ag, 2022) Temiz, Abdurrahim; Yasar, Mustafa; Koc, ErkanA casting technology based on the infiltration method was used to fabricate a controllable porous Mg alloy structure. The porous structure was designed as a gyroid structure, which is one of the well-known triply periodic minimal surface structures. The model used as a placeholder was produced in a stereolithography apparatus and embedded in NaCl as a mold. In order to define the mechanical properties, sheep bone was cut to the same size as the gyroid structure and these were then analyzed under compression loads. The compression test results were compared with each other and with the Young's moduli of human trabecular bone as stated in the literature. The results of the compression tests indicated that the Young's modulus of the gyroid structure obtained from experimental data was in the range of the Young's moduli of human trabecular bone but lower than the Young's modulus of the sheep bone obtained from the experimental data. A finite element model of the gyroid structure was designed using the LS-Dyna module in ANSYS Workbench and validated with experimental test results. In addition, finite element analysis of the circular cross-sectional beam was also carried out and compared with the gyroid structure in order to evaluate the deformation and fractures. GraphicÖğe FABRICATION OF OPEN-PORE BIODEGRADABLE MAGNESIUM ALLOY SCAFFOLD VIA INFILTRATION TECHNIQUE (Apr, 10.1007/s40962-021-00604-9, 2021)(Springer Int Publ Ag, 2022) Temiz, Abdurrahim; Yasar, Mustafa; Koc, ErkanA correction to this paper has been published: https://doi.org/10.1007/s40962-021-00616-5Öğe Forming sheet metals by means of multi-point deep drawing method(Elsevier Sci Ltd, 2007) Yasar, Mustafa; Korkmaz, Zeki; Gavas, MummerMulti-point deep drawing (MPDD) is an advanced manufacturing technology for 3D sheet metal parts and it can form a variety of part shapes without the need for solid dies. In this study, a test set has been prepared for multi-point deep drawing process utilizing the multi-point forming technology. Drawability attributes of gradually rectangular shaped container have been observed using a sheet, which has the quality of Erdemir 7114 and is suitable for deep drawing process, and also using multi-pointed punch with a given tool geometry and a draw velocity. The blank shape to be drawn without wrinkling and tearing has been determined. Wrinkles and dimples are the major forming defects in the MPDD process. In conventional deep drawing, the method to form sheet metal with a blank holder is an effective way to suppress wrinkling; and the same is true in MPDD. The process of multi-point forming technology decreases production cost of die, provides flexible usage, and it is convenient to achieve the most even deformation distribution. (c) 2006 Elsevier Ltd. All rights reserved.Öğe Investigation of wear behaviors of C95200-C95300 Cu-Al-Fe alloys(Emerald Group Publishing Ltd, 2009) Yasar, Mustafa; Demiral, Mustafa; Ozyurek, Dursun; Unal, MehmetPurpose - The paper's aim is to examine dry friction properties of the wear behaviors of the manufactured aluminum bronzes (C9500 and C95300) by using pin-on-disk type wear test device. Design/methodology/approach - In this study, alloys were produced by casting C95200 and C95300 aluminum bronzes norms. Produced aluminum bronzes ingot after homogeneous were formed for wearing specimen. These test were conducted on two different alloys, in the sliding velocities 1, 1.5 and 2 m/s, with four different load (25, 37.5, 50 and 62.5 N) and for four different space (500, 1,000, 2,000 and 4,000 m). Wearing specimens tested for hardness and investigated in order to spectral electron microscope photographs. Findings - After investigation, C95200 grain size was bigger than C95300. Furthermore, C95300 alloys were harder than C95200 because of more aluminum. Increasing load, sliding velocity and distance causes increasing wear. Coefficient of C95200 alloys was higher than C95300. Research limitations/implications - Aluminum bronzes show different properties according to the additional elements in them. Reliability of aluminum bronzes can be achieved by the control of chemical composition and the manufacturing method. Practical implications - Very useful information for industries using or planning to produce C95200 and C5300 alloys is provided. Originality/value - This paper identifies a resource need and offers practical help for a manufacturing operation.Öğe Manufacturing of Wear Resistant Iron-Steel: A Theoretical and Experimental Research on Wear Behavior(Eos Assoc, 2021) Bildik, Oguzhan; Yasar, MustafaIn this study, four different alloys of steel blocks with a thickness of 15mm were manufactured in order to develop an alternative to steel plates used in wear exposed areas of construction machines, trucks, and asphalt production plants. To further increase the wear resistance of the manufactured steel blocks, their thickness was reduced to 10mm by the hot-rolling method. Wear specimens were obtained from rolled blocks. These specimens were abraded at 20N, 40N, and 60N loads in reciprocating linear motion module ASTM G-33 standards to determine their wear resistance. SEM and EDX analyses were also conducted to see modifications on the worn surfaces. In addition, a theoretical model of wear behaviors was created, calculations were made with Archard wear equation and ANSYS software, and the theoretical and experimental results were compared.Öğe The theoretical and experimental investigation of blank holder forces plate effect in deep drawing process of AL 1050 material(Elsevier Sci Ltd, 2008) Demirci, H. Ibrahim; Yasar, Mustafa; Demiray, Kemal; Karali, MehmetThe plastic forming process of sheet plate takes an important place in forming metals. The traditional sheet plate forming techniques used in industry are experimental and expensive methods. Prediction of the forming results, determination of the punching force, blank holder forces and the thickness distribution of the sheet metal will decrease the production cost and time of the material to be formed. With this aim, firstly simulation was realized with taking the contact model, material specifications into consideration by using non-linear explicit finite elements method (ANSYS LS-DYNA). In the analysis, the effects of fixed blank holder forces on the wall thickness distribution and wrinkles were examined. As a result of the analysis, without the sheet metal wrinkling or exceeding the tearing limits, for smooth drawings of blank holder the required forces were determined. The results were evaluated and experiments were done with the forces which were determined earlier. As a result of the experiments, which were done with the results obtained with finite elements method, 90% consistency between the experimental and theoretic results was seen. (c) 2007 Elsevier Ltd. All rights reserved.
