Yazar "Bagci, Mehmet" seçeneğine göre listele
Listeleniyor 1 - 9 / 9
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Application of Taguchi method on optimization of testing parameters for erosion of glass fiber reinforced epoxy composite materials(ELSEVIER SCI LTD, 2013) Bagci, Mehmet; Imrek, HuseyinThe target of this experimental study is to investigate solid particle erosion behavior of a new composite material formed by adding boric acid particles to glass fibers and epoxy resin at an amount of 15% and 30%. The tests which involved angular aluminum particles with two different sizes were conducted at different conditions of impact velocities, fiber directions and impingement angles. The test specimens were characterized by techniques of X-ray diffraction (XRD) and scanning electron microscope (SEM). In addition, the design of the experiments which utilizes Taguchi's orthogonal arrays approach was used and an optimal parameter combination determined which led to minimization of erosion rate of the composites. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.Öğe Cryogenic machining of carbon fiber reinforced plastic (CFRP) composites and the effects of cryogenic treatment on tensile properties: A comparative study(ELSEVIER SCI LTD, 2018) Morkavuk, Sezer; Koklu, Ugur; Bagci, Mehmet; Gemi, LokmanCarbon fiber reinforced plastics (CFRPs) are prone to damage locally during machining due to the applied cutting forced and generated heat. Cryogenic machining can reduce the heat generated damages of CFRPs by utilizing cryogenic liquids instead of conventional cutting fluids. The goal of this study is to investigate milling performance of CFRPs in cryogenic medium. For this, a new cryogenic machining approach was adopted to slot milling of CFRPs by submerging the workpiece within a cryogenic liquid. The CFRPs were fabricated via vacuum assisted resin transfer method by using woven carbon fiber fabric as a reinforcement and epoxy as a matrix. Machining performance was evaluated based on the resulting cutting force, delamination factor, surface roughness, and surface damage. Moreover, the influences of cryogenic coolant on the tensile properties, fracture surface microstructure, and machined surface of the CFRP laminates were analyzed with scanning electron microscopy (SEM). SEM analysis revealed that combination of different damage modes such as debonding, micro matrix crack, fiber pull out, and bundle pull out, delamination, and fiber breakage were observed. The results showed that cryogenic machining approach provided less damage formation on the machined surface, reduced delamination factor and surface roughness but increased resulting cutting force during machining of the CFRPs. On the other hand, there was a slight improvement (about 3%) of the tensile properties for the CFRPs exposed to cryogenic coolant due to matrix hardening and increasing in the fiber strength and shear strength.Öğe Determination of solid particle erosion with Taguchi optimization approach of hybrid composite systems(ELSEVIER SCI LTD, 2016) Bagci, MehmetThis empirical study investigates the solid particle erosion wear behavior of a new composite material made of glass fiber and epoxy as the main materials and (Al2O3+SiO2) particulates added into the structure at the amount of 30% [15% (Al2O3)+15% (SiO2)] of the resin used for the composite. The tests were carried out by selecting three different impact velocities (23, 34, 53 m/s), three different impingement angles (30 degrees, 60 degrees, 90 degrees) and angular alumina erodents having approximate sizes of 200 mu m. The fiber directions were used 0/90/0, 45/-45/45 and 90/0/90. An erosion test facility at room temperature and Taguchi's orthogonal arrays were used for experimentation. Moreover, an optimal parameter combination was determined, which led to minimization of erosion rate (ER). (C) 2015 Elsevier Ltd. All rights reserved.Öğe The effects of solid particle erosion of zm coating material on Gf/Ep and Cf/Ep composites by using PVD method(GAZI UNIV, 2019) Bagci, MehmetProtective coatings produced by using Physical Vapour Deposition (PVD) method can increase the life time of the components. Therefore; in this study, approximate to 0.25 mu m thickness ZrN coatings are applied on Glass Fiber Reinforced Epoxy (GF/EP) and Carbon Fiber Reinforced Epoxy (CF/EP) composites by magnetron sputtering to gain an improved understanding of the erosion resistance. The impingement angles used in the tests were 30 degrees, 60 degrees and 90 degrees, while the impact velocity was 53 m/s. Al2O3 abrasive particles with an average diameter of 200 mu m was used. All test specimens regardless of their various properties exhibit maximum erosion rates at 30 degrees impingement angle and thus exhibiting similar behavior as that observed for ductile materials. Optic microscopic views were performed on the surfaces in order to characterize the erosion mechanism. The erodent particles of the both coating layer and composite matrix were found of main role in governing the wear progression. The measured erosion rates were sensitively correlated with the material removal process in order to explain the changes within the coated interfaces.Öğe Erosion wear performance of borax filled novel hybrid composites by using the Taguchi experimental design(EMERALD GROUP PUBLISHING LTD, 2016) Bagci, Mehmet; Imrek, HuseyinPurpose - This study aims to examine solid particle erosion behavior of novel hybrid composite materials where borax (B2O3) particles (similar to 150 mu m) were added to glass fabric and epoxy resin at an amount of 15 and 30 per cent. Design/methodology/approach - The tests that involved slightly rounded and irregular Al2O3 particles having two erodent sizes (200, 400 mu m) were conducted at these operational conditions; namely, three impact velocities (23, 34, 53 m/s), two fabric directions (0/90/0, 45/-45/45) and three impingement angles (30 degrees, 60 degrees, 90 degrees). In addition, the design of experiments, which utilizes Taguchi's robust orthogonal arrays approach, was used and an optimum parameter combination was established, which had a minimum erosion rate. Moreover, scanning electron microscope and X-ray diffraction views show the visual effect of filler material. Findings - All test specimens regardless of their dissimilar characteristics displayed maximum erosion rate at 30 degrees impingement angle. Test specimens with 45/-45/45 fabric direction are more wear-resistant than their counterparts with 0/90/0 fabric direction. The erosion wear of glass fabric reinforced epoxy (GF/EP) composites whose matrix had 15 per cent addition of borax particles was higher than that of neat GF/EP composites. In addition, new composite material formed by including borax particles at a rate of 30 per cent of resin leads to a reduction in erosion rates. Originality/value - While fabric-reinforced polymers take place in most of the studies conducted on erosive wear of composites, studies involving erosion on composites with filler materials can hardly be encountered.Öğe Erosive Wear of Glass Fiber and B2O3 Reinforced Epoxy Composites(TRANS TECH PUBLICATIONS LTD, 2011) Bagci, Mehmet; Imrek, HuseyinIn this experimental study, erosive wear behavior of epoxy-resin dipped composite materials reinforced with glass fiber and B2O3 (borax) under different impact velocities, erodent sizes, and erodent striking angles along the fiber direction were investigated. The tests which involved slightly rounded and irregular silicon oxide (SiO2) particles having two different sizes of approximately 250 mu m and 500 mu m, were conducted at two different impact velocities of approximately 20 m/s and 40 m/s, two different fiber directions (0 degrees and 45 degrees) and six different impingement angles of 15 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees and 90 degrees. In the test results, erosion rates were obtained as functions of impact velocities, striking angles, fiber direction and particle sizes. In addition, the microscopic views showing worn out surfaces of the glass fiber reinforced epoxy composites were scrutinized.Öğe Optimization of Test Parameters That Influence Erosive Wear Behaviors of Glass Fiber-Reinforced Epoxy Composites by Using the Taguchi Method(ASME, 2015) Bagci, Mehmet; Imrek, Huseyin; Khalfan, Omari MashiThis study describes the development of a multicomponent composite system consisting of thermoplastic epoxy resin reinforced with E-glass fiber and silicon dioxide (SiO2) particles and investigates its erosion behavior under different operating conditions. Due to the increasing importance of composites in engineering applications and the need to tackle solid particle erosion in various industrial sectors, the study aims at finding how these composites behave in such type of wear. The composite specimens used for the tests were classified into three types; pure glass fiber (GF)-epoxy, those with addition of SiO2 particles at an amount of 15% and the last group had SiO2 particles added at 30% of the resin used for the materials. The experiments were carried out by selecting three different impact velocities, three different impingement angles, and angular alumina abrasive particles having approximate sizes of 200 mu m. The fiber directions used were 0/90/0 and 45/-45/45. SEM views belonging to the specimens were taken before and after the tests in order to investigate the differences and the causes of the surface damages. Moreover, it is found that the Taguchi's robust orthogonal array method provides a simple, systematic, and efficient methodology for the optimization of the erosion wear parameters. At the end of the tests, the most significant factor in affecting the erosion rate is found to be the impingement angle, followed by the impact velocity, fiber direction, and filler material.Öğe Solid Particle Erosion as Influenced by Tensile Axial Loads(TAYLOR & FRANCIS INC, 2011) Imrek, Huseyin; Bagci, Mehmet; Khalfan, Omari MashiIn this study, the effects of external loads and impingement angle on erosive wear of AISI 1010 steels were investigated. Tensile axial loads corresponding to 0, 20, 40, and 60% of the specimen material's yield strength were applied on specimens attached to a specially designed specimen holder. The erosion tests were conducted at impact angles of 15, 30, 45, 60, 75, and 90. for each loading. Particles with angular geometry were used as abrasive steel grits and their impact velocities were adjusted by changing air pressure. The impact velocity of the particles was set at 30 m/s. Graphs of erosion rates as a function of stress and impact angles were constructed based on specimens' weight loss obtained at the end of the tests. It was found that there was a slightly increase in erosion rate as a result of increased tensile stress. It was also found that the erosion rate increased between 0 and 30 degrees, whereas between 30 and 90 degrees impingement angles, the erosion rate was seen to fall.Öğe Solid particle erosion behaviour of glass fibre reinforced boric acid filled epoxy resin composites(ELSEVIER SCI LTD, 2011) Bagci, Mehmet; Imrek, HuseyinThe tests which involved angular aluminium (Al(2)O(3)) particles with two different sizes of approximately 200 and 400 mu m were conducted at the operating conditions namely different impact velocities of approximately 23, 34 and 53 m/s, two different fibre directions [0 degrees (0/90) and 45 degrees (45/-45)] and three different impingement angles of 30 degrees, 60 degrees and 90 degrees. New composites with addition of Boric Acid filler material at 15% of resin exhibited upper wear than the neat materials without filler material. This means the filler material has decreased the erosion wear resistance. SEM views showing worn out surfaces of the test specimens were scrutinised. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
