Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2019Investigation of Structural Properties and Wear Behavior of Surface Treated AZ31 Mg Alloy
Çelik, İlhan
Magnesium (Mg) and its alloys have a low density. For this reason, they are recognized as light metallic materials. Magnesium and its alloys have the potential capability to be widely used especially in the automotive, aviation and biomedical applications. However, their wear and corrosion resistance are very poor, so their area of usage is limited. This situation may adversely affect their usage without surface treatment despite their relatively well mechanical properties. Arc PVD technique was used to increase the wear resistance of AZ31 Mg alloy in this study. The surface coating process was applied to AZ31 Mg specimens as desired. Microstructural and morphological studies were done with XRD and SEM appliances. Pin-on-disc wear tests were performed to determine tribological properties. Through this study it was determined that AZ31 Mg alloy showed superior mechanical properties after applied CrN coating.
- 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 künye2016Crn kaplanan saf titanyumun yapısal ve tribolojik özelliklerinin incelenmesi
Çelik, İlhan
Temas halinde çalışan makine elemanlarının bulunduğu uygulamalarda veya korozif ortamlarda kullanılan mühendislik malzemelerinin kullanım ömürlerini uzatmak için genellikle yüzey kaplama yöntemlerinden yararlanılmaktadır. Bu kaplama yöntemlerinin en önemlilerinden bir tanesi PVD kaplama işlemidir. PVD kaplama, birçok mühendislik uygulamalarında kullanılan makine elemanlarının yüzey özelliklerini iyileştirmek için yaygın bir şekilde kullanılmaktadır. Bu çalışmada, sahip olduğu mükemmel korozyon direnci, yüksek dayanım/ağırlık oranı ve biyouyumluluk gibi üstün özelliklerine karşın zayıf aşınma direnci nedeniyle kullanım alanları kısıtlanmakta olan saf titanyumun (Kalite 2) yüzeyine PVD yöntemi kullanılarak CrN kaplanmıştır. Kaplanmış ve kaplanmamış numunelerin aşınma davranışları tribolojik uygulamalar için incelenmiştir. CrN kaplanmış numunelerin yüzey morfolojisi ve mikroyapısı XRD ve SEM cihazları yardımıyla incelenmiştir. Aşınma deneyleri pin-on-disk cihazında yapılmıştır. Çalışma sonucunda, CrN kaplanmış numunelerin kaplanmamış numunelere göre daha yüksek yüzey sertliğine ve daha iyi aşınma direncine sahip olduğu görülmüştür
- MakaleYalnız künye2016Structure and surface properties of Al2O3–TiO2 ceramic coated AZ31 magnesium alloy
Çelik, İlhan
Magnesium and its alloys are the engineering materials which have the potential ability to be able to used widely particularly in the automotive, aerospace and in the biomedical sectors, especially thanks to their features such as lightness, specific strength that they have and biocompatibility. However, due to their poor wear resistance and corrosion resistance, the areas of usage are being restricted. This situation prevents Mg alloys to be used without any surface protection despite their good mechanical properties such as high strength/weight ratio. In this study, plasma spraying method is used to improve the poor corrosion resistance of AZ31 Mg alloy. Al2O3–13 wt% TiO2 (AT13) and Al2O3–40 wt% TiO2 (AT40) composite ceramic coatings were coated successfully on the surfaces of AZ31 Mg samples. The wear properties of the AT13 and AT40 coated samples were investigated for tribological applications. Surface morphology and microstructure of the duplex treated samples were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The microhardness value of the uncoated AZ31 Mg alloy is 40±3 HV0.1, while the microhardness values of the AT40 and AT13 coatings are enhanced to 800±39 HV0.1 and 1500±35 HV0.1, respectively.