Mechanical Engineering / Makina Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/4129
Browse
11 results
Search Results
Research Project Seramik matriks kompozitlerin düşük sıcaklıklarda polimer piroliz yöntemi ile üretimi ve karakterizasyonu(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2004) Tanoğlu, Metin; Akkaş, Hatice Deniz; Öveçoğlu, M. LütfiSeramik matriks kompozit (SMK) ler önseramik polimerlerin pirolitik dönüşümü kullanılarak geliştirilmiştir. İlk olarak, fenil (PPS) ve metil (PMS) ihtiva eden polisiloksanlar, ısıl dönüşümleri ve faz oluşumlarının incelenmesi için dolgu malzemesi ilave edilmeden, değişik piroliz sıcaklıklarında (900-1500°C) ve argon atmosferinde piroliz prosesine tabi tutulmuştur. Bunun sonucunda, 1300°C'ye kadar inert atmosferde gerçekleşen piroliz ile polimerlerin amorf silikon oksikarbür (SiOxCy) seramiklerine dönüştüğü gözlenmiştir. Daha yüksek sıcaklıklardaki dönüşümler beta -SiC kristallerinin oluşumuna sebep olmuştur. SMK'lar, ağırlıkça % 60-80 oranında değişen aktif ve inert dolgular ilave edilerek 15 MPa basınç altında sıcak preslemeyle polimerize edilmiş, inert argon ve reaktif azot atmosferinde 900-15 00°C arasındaki sıcaklıklarda piroliz ile üretilmiştir. Dolgu tipi ve oranının, piroliz sıcaklığı ve atmosferin faz oluşumlarına etkileri XRD, SEM-EDX ve TGA yöntemleriyle incelenmiştir. Sonuçlar, Ti gibi aktif bir dolgu maddesinin kullanılması durumunda aktif dolgunun polimerin bozunma ürünleri ile reaksiyonu sonucu amorf matriks içerisinde TiC, TiSi, ve TiO v.b. kristallerin oluştuğunu göstermiştir. Bunun yanında, inert SiC ilaveli kompozitlerde herhangi yeni faz oluşumu gözlenmemiştir. Aktif dolgu kontrollü polimer piroliz (AFCOP) tekniğinin etkilerini incelemek için SMK'ların kütle kaybı ve yoğunluk artışı değerleri ölçülmüştür. Seramik yapılara aktif dolgu ilave edilmesi durumunda, polimer oranının düşmesi ve dolgu malzemesi ile polimer arasındaki reaksiyonların sonucu olarak kütle değişimleri belirgin şekilde etkilenmiştir. Dolgusuz PPS ve PMS numunelerinde 1500°C'de piroliz işlemi sonucu ölçülen % 27 ve 17 'lik kütle kaybının, kompozit sistemlerinde % 2 seviyelerine kadar düştüğü görülmüştür. Vickers Sertlik testleri ile yapılan mekanik özellik karakterizasyonları SiOC esaslı seramiklerin maksimum sertlik değerlerine (dolgusuz PPS için 8.88 GPa, dolgusuz PMS için 10.67 GPa) çatlaksız ve en az gözenek içeren numunelerin üretildiği optimum sıcaklık olan 1100°C'de ulaşıldığını göstermiştir. Ti ilaveli kompozit sistemlerde ise sertlik değerleri 14 GPa kadar çıkmıştır.Article Poliamid 6/6 (pa 66) Mikrofiberler ile Toklaştırılmış Tabakalı Kompozitlerin Mod-ı Delaminasyon Direncinin İstatiksel Analizi(Niğde Ömer Halisdemir Üniversitesi, 2019) Beylergil, Bertan; Tanoğlu, Metin; Aktaş, EnginFiber takviyeli kompozitler, ağırlıklarına oranla yüksek mukavemet ve rijitlikleri nedeniyle uzay ve otomotiv yapısal parçalarında yaygın olarak kullanılmaktadır. Delaminasyon, bu kompozitlerde görülen en yaygın ve kritik hasar modudur. Bu kompozitlerin delaminasyon direncini arttırmak amacıyla, nanokatkılar ile epoksi toklaştırması, dikişleme, z-pimler ve arayüzeyde mikro/nanofiber kullanılması gibi pek çok sayıda teknik geliştirilmiştir. Bu çalışmada, poliamid 6/6 (PA 66) mikrofiberler ile toklaştırılmış karbon fiber/epoksi kompozitlerin Mode-I delaminasyon direnci Weibull dağılımı kullanılarak istatiksel olarak analiz edilmiştir. Test verilerinin istatiksel olarak değerlendirilmesi sonucunda PA 66 mikrofiberlerin kullanılmasının %90 güven seviyesinde kırılma tokluğunu yaklaşık %445 mertebesinde arttırdığı gözlemlenmiştir.Conference Object Citation - Scopus: 1Development of Composite Drive Shaft Tube for Automotive Industry(Applied Mechanics Laboratory, 2019) Arslan Özgen, Gizem; Tanoğlu, Metin; Aktaş, Engin; Yücetürk, KutayWeight, vibration, fatigue, and critical speed limitations have been recognized as serious problems in drive shafts in automotive industry for many years. Conventional drive shaft is made up into two parts to increase its fundamental natural bending frequency. This present work deals with the replacement of conventional steel drive shaft with a composite counterparts. The benefits of eliminating the two piece shafts are significant reductions in weight, noise, vibration and harshness. In this work, one-piece propeller shaft composed of carbon/epoxy and glass/epoxy composites have been designed and manufactured for a rear wheel drive automobile. The performance measures are static torque transmission capability, torsional buckling and the fundamental natural bending frequency. The tubular composite shaft samples are being manufactured by using filament winding technique. To predict the torsional properties, fatigue life and failure modes of composite tubes for different fiber orientation angle and stacking sequence, finite element analysis (FEA) has been used. The predicted and experimental values has been reported for comparison. The next phase of work consists of optimization of shaft for the objective function as weight and fundamental natural frequency considering different stacking sequence and fiber orientation. © CCM 2020 - 18th European Conference on Composite Materials. All rights reserved.Article Citation - WoS: 31Citation - Scopus: 33Modification of Carbon Fibre/Epoxy Composites by Polyvinyl Alcohol (pva) Based Electrospun Nanofibres(Adcotec Ltd., 2016) Beylergil, Bertan; Tanoğlu, Metin; Aktaş, EnginIn this study, the effects of modifying interlaminar region of unidirectional carbon fibre/epoxy composites by the incorporation of electrospun polyvinyl alcohol (PVA) nanofibres were investigated. PVA nanofibres were directly deposited onto the carbon fabrics by electrospinning method to improve mechanical performance of those composites. The features of the electrospun nanofibres were characterized by microscopy techniques. The unidirectional carbon fibre/epoxy composite laminates with/without PVA nanofibre interlayers were manufactured by vacuum-infusion technique in a [0]4 configuration. Tensile, three-point bending, compression, Charpy-impact and Mode-I fracture toughness tests (Double Cantilever Beam (DCB)) were carried out in accordance with ASTM standards to evaluate mechanical performance of the composites. Scanning electron microscopy (SEM) observations were made on the specimens to evaluate microstructural features. It was observed that the carbon fabrics were successfully coated with a thin layer of PVA nanofibres by electrospinning technique. The results showed that P VA nanofibres improve the mechanical properties of unidirectional carbon/epoxy composite laminates when subjected to in-plane loading. On the other hand, PVA nanofibres slightly reduced the mode-I fracture toughness values although they led to more stable crack propagation.Book International Porous and Powder Materials Symposium and Exhibition Ppm 2015, 15-18 September 2015, Izmir-Turkey(Organizing Committee of the International Porous and Powder Materials Symposium and Exhibition, 2015) Polat, Mehmet; Tanoğlu, Metin; Kılıç Özdemir, Sevgi; Polat, Mehmet; Tanoğlu, MetinWe welcome you to the International Porous and Powder Materials Symposium and Exhibition, PPM 2015. The foreword of the proceedings and the abstracts books of the previous symposium, PPM 2013 which was the first of its series, started with the following sentence: ‘Idea of organizing a symposium on porous and powder materials owes its germination to the curiosity about the “other side of the fence”.’ It was a very fitting and almost a prophetic statement because 700 participants from 50 countries hosted by PPM 2013 belonged to an incredibly wide spectrum of science and technology, who one way or another dealt with porous and powder materials. It was both a fascinating and engaging sight to have people from the cement industry sitting in the sessions related to Biological and Medical Aspects since they realized that a characterization technique used in this field may actually answer some questions in theirs. Do we not deal with the same basic questions when we truly try to understand a material no matter where it originates from or how it is being put into application?Book International Porous and Powder Materials Symposium and Exhibition Ppm 2013, 3-6 September 2013, Çeşme Izmir-Turkey(Organizing Committee of the International Porous and Powder Materials Symposium and Exhibition, 2013) Özdemir, Sevgi Kılıç; Polat, Mehmet; Tanoğlu, Metin; Kılıç Özdemir, Sevgi; Polat, Mehmet; Tanoğlu, MetinWe welcome you to the first of the International Porous and Powder Materials Symposium and Exhibition, PPM 2013. The idea of organizing a symposium on porous and powder materials owes its germination to the curiosity about the ‘other side of the fence’. We are all familiar of the mild surprise when we come accross with a research paper from a totaly unrelated field written in a completely different terminology but describing something pleasantly familiar. Just imagine the elation of a PhD student in ceramics who is trying to optimize the stability and plasticity of the green body reading about the double layer around a protein, of an environmental engineer who is attempting to flocculate a nasty sludge coming accross with the concept of aggregation of micellar structures or of a researcher in chemical engineering who is looking for the perfect catalyst seeing the SEM pictures of porous nanoparticles developed for drug delivery. The list could be extended with much better examples by the readers of this book. But the best set of words to describe these feelings is an awareness of wholeness and solidarity.Conference Object Citation - Scopus: 1Silver and Zinc Oxide Based Nano Powders and Their Polymer Based Nanocomposites for Antibacterial Application(European Conference on Composite Materials, 2014) Abatay, Ezgi; Özmen, Tuğçe; Arslanoğlu, Alper; Tanoğlu, MetinThe microorganisms cause some serious infections. It is a requirement and a necessity to create sterile fields such as hospital, food processing and public places. Composite stones are one of the main building materials that have been used in buildings due to their high resistant to abrasives, chemicals and mechanical impacts. The silver (Ag), zinc oxide (ZnO), and also nano Ag loaded ZnO (ZnO/Ag) nanopowders have demonsrated capability for the preparation of the polymer based antibacterial nanocomposite materials. In this study, Ag/polyester, ZnO/polyester, Ag/ZnO/polyester and their nanocomposites were prepared and tested with various weight fractions. The microstructure and surface morphology of these nanocomposites were investigated by means of scanning electron microscopy (SEM/EDX). The thermal properties were analyzed by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Finally, The antibacterial properties of nanocomposites were analyzed against gram positive (Bacillus subtilis) and gram negative bacteria (Escherichia coli).Article Citation - WoS: 18Citation - Scopus: 20Thermal Curing Behavior of Mwcnt Modified Vinyl Ester-Polyester Resin Suspensions Prepared With 3-Roll Milling Technique(John Wiley and Sons Inc., 2009) Seyhan, Abdullah Tuğrul; De La Vega, Alejandra; Tanoğlu, Metin; Schulte, KarlThis study aims to investigate the curing behavior of a vinyl ester-polyester resin suspensions containing 0.3 wt % of multiwalled carbon nanotubes with and without amine functional groups (MWCNTs and MWCNT-NH2). For this purpose, various analytical techniques, including Differential Scanning Calorimetry (DSC), Fourier infrared spectroscopy (FTIR), Raman Spectroscopy, and Thermo Gravimetric Analyzer (TGA) were conducted. The resin suspensions with carbon nanotubes (CNTs) were prepared via 3-roll milling technique. DSC measurements showed that resin suspensions containing CNTs exhibited higher heat of cure (Q), besides lower activation energy (Ea) when compared with neat resin. For the sake of simplicity of interpretation, FTIR investigations were performed on neat vinyl ester resin suspensions containing the same amount of CNTs as resin. As a result, the individual fractional conversion rates of styrene and vinyl ester were interestingly found to be altered dependent on MWCNTs and MWCNT-NH2. The findings obtained from RS measurements of the cured samples are highly proportional to those obtained from FTIR measurements. TGA measurements revealed that CNT modified nanocomposites have higher activation energy of degradation (Ed) compared with the cured polymer. The findings obtained revealed that CNTs with and without amine functional groups alter overall thermal curing response of the surrounding matrix resin, which may probably impart distinctive characteristics to mechanical behavior of the corresponding nanocomposites achieved.Conference Object Effect of Blending Conditions on the Properties of Epdm/Organoclay Nanocomposites(IOM Communications Ltd., 2009) Karşal, Çiçek; Tanoğlu, Metin; Odabaş, Sibel; Ersoy, Osman G.; Karakaya, NurselThe effects of blending conditions on the microstructural and mechanical properties of EPDM / organo modified montmorillonite (OMMT) nanocomposites at various clay loadings were investigated. The effects of the processing conditions were manifested in both the morphology and mechanical properties, which showed significant increase when optimized process conditions are applied.Conference Object Alüminyum Köpük Dolu Kompozit/alüminyum İkili Tüplerin Ezilme Davranışları(Pamukkale Üniversitesi, 2006) Yüksel, Sinan; Tanoğlu, Metin; Güden, MustafaTüp sarma yöntemiyle hazırlanan ince duyarlı cam fiber takviyeli polyester kompozit/Alüminyum ikili tüplerin ezilme davranışları statik basma hızlarında (25 mm/dak) deneysel incelenmiştir. Tüplerde dolgu malzemesi olarak kullanılan Al köpüğün ezilme yük değerlerine ve deformasyon mekanizmalarına etkileri belirlenmiştir.