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Sürdürülebilir Kalkınma Amaçları

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• MakaleAçık Erişim2025/r/gumushane/13930
  Experimental determination of the compression behavior of RTV silicone rubber-based magnetorheological (MR) materials under static loading

  Mazlum, Ugur; Celik, Ilhan

  In this study, MR elastomer (MRE) materials were produced using seven different types of silicone rubber and five different types of magnetically sensitive ferromagnetic powders. The MRE materials were obtained in three states: pure, isotropic (homogeneous), and anisotropic (aligned). Compression tests were conducted using a uniaxial testing machine, with engineering stress–strain curves, tangent modulus, and MR-strain behavior graphs generated, considering powder ratio, powder type, and hardness values. The goal was to investigate the positive effects of magnetic field influence on these parameters and how the alignment state affected the stress performance of the materials. As a result, the highest stress increase at 10% strain was observed in materials containing 40% powder, with magnetic field comparison showing the most significant results. With the EM powder type at a 30% powder ratio in the isotropic state, a 563% increase in stress was obtained. Among the matrix materials with the same hardness, the most robust material was determined to be the MM240 TV with a Shore hardness of 40. Furthermore, the most significant increase in tangent modulus under the influence of the magnetic field was observed in vertically aligned materials. Compared to the pure material, a 3127% increase was found at 0.57% strain in vertically aligned samples. In materials with Shore hardness of 2, using Basf CN powder at 10–40% powder ratios, the highest relative MR effect was observed at a 20% powder ratio. The stress increase for vertically aligned samples compared to the pure state was 1274.6% at 0.27% strain. When comparing the relative MR effect of materials with Shore hardness between 10 and 59, the largest increase was obtained from the Sorta Clear matrix material.

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• MakaleYalnız künye2023/r/gumushane/12693
  Determination of shear behavior of magneto-rheological elastomers under harmonic loading

  Mazlum, Ugur; Celik, Ilhan

  Magneto-rheological (MR) materials can respond reversibly and quickly under the effect of an external magnetic field. MR materials contain micron-sized iron particles. These iron particles are typically dispersed in an elastomer or a liquid. These materials due to their properties constitute a kind of smart material in terms of engineering material. Such materials are used as isolators in various engineering applications, structures, and sound control subsystems. This study aimed to determine the mechanical properties for shear behavior of MR materials for under harmonic loading. Parameters such as matrix materials with different hardness values, powder types, magnetic field, frequency, and deformation were studied. The parameters related to the MR material itself were analyzed with the obtained data. The present study reveals that considering the sensitivity to magnetic field parameter, composite materials having the most suitable properties were produced with Shore 2 hardness value and SQ magnetic powder. It had been observed on increase about 200% at the rate of Shore A10 and A2 as a result of comparing the hardness scale. Also according to the powder rate while there was an increase on worth effect of relative MR, it is seen that the biggest increase had been in SQ powder with 199% worth. When looked some studies in literature, about comparing different hardness values such as matrix materials powder types etc. there aren’t any studies. The state of magnetic field thinks that features such as MR effect, Storage, and Loss modulus haven’t been examined yet.

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• MakaleAçık Erişim2020/r/gumushane/17898
  Normalized stress relaxation behaviors of SBR, NBR, NR and EPDM synthetic rubber species

  Mazlum, Uğur

  Rubber-like materials are used in different application areas considering the developing technology. However, inelastic properties such as stress relaxation, which prevent the mechanical properties of such materials from being fully understood. In addition, the lifetimes of rubber-type materials with different elongation rates can be obtained by normalizing the stress-time data obtained from the stress relaxation test of the material and drawing it on a 0-1 stress scale. In this study, normalized stress relaxation tests were performed using four types of rubber, three hardness values and two different procedures. As a result, although the increase of hardness decreased the tensile value by 9%, it was observed that the increase in tensile values between the procedures was at the maximum of 7.3% i n t he N R r ubber m aterial a nd i n t he p re-procedural state. Therefore, applying preliminary procedures before the experiments increases the lifetimes of the materials to a certain extent depending on the material characteristics.

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• MakaleYalnız künye2019/r/gumushane/15016
  Production of silicone-based composite doped with waste NdFeB magnet and determination of mechanical properties by transforming experimental results into images

  Çelik, İlhan; Akben, Selahaddin Batuhan; Mazlum, Uğur

  Waste neodymium–iron–boron (NdFeB)-doped silicon-based magnetic polymer composites are obtained by mixing the double-doped mixtures with a 70–30% ratio. In this study, composite materials were produced by adding NdFeB magnetic particles with sizes between 0–45, 45–63, 63–125, and over 125 (µm), and compression experiments were carried out to determine the mechanical properties of them. Experimental results were transformed into images and then analysed using image processing methods. According to the analysis of images representing the results of compression experiments, the strength values of NdFeB–RTV (vulcanized at room temperature) silicone rubber have increased by increasing the magnetic powder ratio. In addition, it was observed that there is a decrease in the elongation at break values due to weakening of polymer chain bonds. Considering the sensitivity of the successfully produced composite materials to the magnetic field, significant improvements in strength values were obtained. It is hoped that these results will lead to an increase in the recycling rate of waste magnets and will prevent environmental damage.

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• MakaleAçık Erişim2017/r/gumushane/15864
  Experimental investigation of the effect of ferromagnetic particles addition on mechanical properties of magneto-rheological materials

  Mazlum, Ugur; Gümrük, Recep

  The ferromagnetic particle, are used in many areas due to their magnetic field sensitivity. Composite MRE materials which obtained from the combination of the matrix material with these particles are classified as a kind of smart materials. In this study, it is aimed that the compressive mechanical properties of MRE materials produced by adding four different magnetic particles in RTV (room temperature vulcanizing) silicone elastomer are investigated. As a matrix material Vario 40 silicone rubber were used, which is common in engineering application. The particle rate inside MRE materials was kept at 30% by volume. In addition, to investigate the influence of orientation of particles inside MRE materials, some samples were subjected to external magnetic field during production. These samples are named as anisotropic MRE materials while the others are described as isotropic ones. The tests showed that anisotropic samples have much more strength values according to isotropic samples. Of all, the MRE samples including BASF CN particles reveal the biggest strength values. Also, the samples were evaluated in terms of MR effect and the largest MR effect with an increase value of 201% was found for anisotropic samples including SQ-I particles with regard to the corresponding isotropic one. As a result, this study determined that the mechanical and MR properties of MRE materials seriously depend on ferromagnetic particle kind and its magnetic characteristic.

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• Derleme MakaleYalnız künye2015/r/gumushane/15928
  EXPERIMENTAL INVESTIGATION OF THE STRESS RELAXATION BEHAVIOURS OF EPDM SYNTHETIC RUBBERS

  Mazlum, Ugur; Vahapoglu, Vahap; Karadeniz, Sami

  Rubber type materials are preferred because they are suitable for use in many engineering applications besides their elasticity. EPDM rubber show outstanding heat, ozone and weather resistance and has excellent electrical properties. Therefore this rubber as an elastomer is an engineering material that has wide range of applications in industry such as door and window seals, radiator, garden and heating hoses, tubing, washers, belts, electrical insulation, roofing membrane and rubber mechanical goods. In this works, the stress relaxation behaviour of EPDM rubber at the room temperature were experimentally investigated. Applied to the hardness EPDM samples were subjected to different loading programs. In addition, for the loading programs that were implemented, it is shown that for the EPDM rubbers tested the stress relaxation curves obtained at different stretch ratios may be represented by a single representative curve for the specimens having the same hardnesses.

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• MakaleAçık Erişim2015/r/gumushane/15869
  INVESTIGATION OF MECHANICAL PROPERTIES OF MAGNETO-RHEOLOGICAL ETHYLENE PROPYLENE DIENE MONOMER AND NATURAL RUBBER TYPE SYNTHETIC RUBBERS FOR BOTH ISOTROPIC AND ANISOTROPIC SITUATIONS

  Mazlum, Ugur; Gümrük, Recep

  Magneto-rheological (MR) materials are in a smart material class that has the rheological properties to be quickly and reversibly controlled with the external magnetic field applications. Considering the technological developments the rubber-like smart materials has had a more functional usage area with magneto-rheological effect. This study investigates the axial mechanical properties of magneto-rheological Ethylene Propylene Diene Monomer (EPDM) and Natural Rubber (NR) type synthetic rubbers for isotropic and anisotropic situations. Also, these composite materials were built by means of hot press systems as either isotropic or anisotropic using magnetic field application after addition of ferromagnetic powders. The influence of magnetic field was investigated. In this study, NR rubber was found to be more susceptible in terms of smart material properties unlike EPDM synthetic rubber.

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