Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2020Normalized 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.
- MakaleYalnız künye2019Production 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.
- MakaleYalnız künye2017Manyeto-reolojik malzemelere ferromanyetik toz ilavesinin mekanik özelliklere etkisinin deneysel olarak incelenmesi
Mazlum, Uğur; Gümrük, Recep
Ferromanyetik toz partikülleri, manyetik alana duyarlılıklarından dolayı günümüzde pek çok alanda kullanılmaktadır. Bu tozların matris malzemeleri ile birleşimlerinden elde edilen kompozit MRE malzemeler sınıflandırılmaktadır. Bu çalışmada, RTV (room temperature vulcanization) silikon kauçuğuna dört farklı manyetik toz ilave edilmesi ile elde edilen kompozit MRE malzemelerinin bası yüklemesi altındaki mekanik özelliklerinin incelenmesi amaçlanmıştır. Matris malzemesi olarak mühendislik açıdan kullanımı yaygın olan Vario 40 silikon kauçuk malzemesi kullanılmıştır. Kompozit MRE malzemelerde toz oranı hacimce %30 oranında tutulmuştur. Ayrıca, tozların yönlenmesinin etkisini incelemek için, üretim esnasında bazı numunelere dış manyetik alan uygulanmıştır. Bu numuneler anizotropik olarak adlandırılırken diğerleri izotropik numunelere olarak adlandırılmıştır. Sonuçlar göstermiştir ki; anizotrop MRE numuneler izotrop numunelere göre çok daha yüksek gerilme değerlerine sahip olmaktadır ve en büyük gerilme artışı BASF CN tozu ilave edilen anizotrop MRE malzemeler için elde edilmiştir. Ayrıca, numuneler MR etki açısından da değerlendirildi ve izotropik versiyonlarına göre %201 gibi bir artış değeri ile en büyük MR etki SQI tozu içeren anizotrop numunelerde gözlemlendi. Sonuç olarak, gerçekleştirilen çalışma ile MRE malzemelerin mekanik ve MR özellikleri, ilave edilen tozun cinsi ve manyetiklik özelliklerine ciddi bir şekilde bağlı olduğu belirlenmiştir
- MakaleYalnız künye2017Experimental Investigation of MR Effect to RTV Silicone Rubber-based Magneto-rheological Materials
Mazlum, Uğur; Gümrük, Recep
Magneto-rheological Elastomers are smart materials whose properties can be altered reversibly and almost instantaneously by application of external magnetic fields. Silicone rubber species are used widely in the laboratory studies because of it is easy to prepare and cured at room temperature. In this study, MRE material was produced using three different types of silicone rubber and ferromagnetic powder which is sensitive to magnetic field. MRE materials are obtained as isotropic (homogenous) and anisotropy (aligned) state. Composite materials were tested in uniaxial compression testing machine with three different test procedures. In this way, the mechanical properties and the magneto-rheological effect of the materials were compared. As a result, under the magnetic field to 0.430 T with anisotropic Sorta Clear40 materials were found to increase in stress 30%, according to the pure state has been demonstrated that the rate of 50%. When the isotropic Sorta Clear40 and Vario40 materials were comparable, MR effect was revealed that the increases the rate of about 325% at strain to 5%. When selecting to optimum rubber types was reached the result should be used to materials the most appropriate to the material characteristics of engineering aspects.