Yazar "Akincioglu, Gulsah" seçeneğine göre listele
Listeleniyor 1 - 5 / 5
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Friction-wear performance in environmentally friendly brake composites: A comparison of two different test methods(Wiley, 2021) Akincioglu, Gulsah; Uygur, Ilyas; Akincioglu, Sitki; Oktem, HasanIn this study, an eco-friendly brake composite sample (EFP) was produced with 3.5% hazelnut shell dust as a natural additive material. Friction tests were performed on the manufactured pad sample and on a commercial pad (CP) using both a Chase-type test machine and a specially designed device. A different approach is presented with the evaluation of the two different test device results. The experimental results were compared using the Taguchi method and it was concluded that the braking performance of the sample with hazelnut shell dust was in accordance with international standards. As a result of the study; the nominal friction coefficient value was found to be 0.505 mu. The shearing force of the EFP and CP samples was measured at 607.3 and 850.5 N, respectively. The friction coefficient values obtained from the EFP and CP samples were in accordance with the SAE J-661 standard and are in the F letter class.Öğe Investigation of the Effect of Cryogenic Treatment Cubic Boron Nitride Turning Insert Tools(Springer, 2021) Akincioglu, GulsahSuperalloys are difficult to process. For this reason, it is important to increase the surface quality of the material and reduce the tool consumption. In the present work, the shallow and deep cryogenically treated performance of cubic boron nitride (CBN) inserts in terms of surface roughness, tool wear, thrust force and chip formation under dry cutting conditions for finish turning of Hastelloy C22. The effect of CBN tools on cutting force, surface roughness, hardness and chip morphology was investigated by applying shallow and deep cryogenic treatment. With the surface roughness values obtained with the deep cryogenic-treated tools (DCT) tool, 137.1% and 73.8% improvements were achieved compared to the RT (Reference tools) and Shallow cryogenic-treated tools (SCT) tools, respectively. DCT and SCT tool were 31.58% and 5.5% lower than the cutting forces obtained with the RT cutting tools, respectively. According to ANOVA analysis, the most effective parameter affecting the surface roughness was determined as the feed with a 67.8% contribution.Öğe A novel study of hybrid brake pad composites: new formulation, tribological behaviour and characterisation of microstructure(Taylor & Francis Ltd, 2021) Oktem, Hasan; Akincioglu, Sitki; Uygur, Ilyas; Akincioglu, GulsahIn the production of brake pad composites, a well-designed new composition formulation plays a key role in improving performance. The purpose of this study; was to investigate the effectiveness of a specifically developed formulation under brake-test conditions. The composition of the brake lining consists of 18 powder materials. As the friction adjuster, Petro-coke powder was used instead of Cashew, which is cheaper and more readily available. The wear tests were carried out in a special design test device simulated close to the real environment. The results obtained have been compared with commercial brake pads. The friction coefficient values decrease with increasing disc temperatures. Brake tests showed that as a friction modifier, petro-coke provided a more effective stabilizer for the friction coefficient and improved the specific wear rate. Also the study can be utilized effectively in determining the friction coefficient and the specific wear rate of designed brake composites.Öğe Taguchi optimization of surface roughness in the turning of Hastelloy C22 super alloy using cryogenically treated ceramic inserts(Sage Publications Ltd, 2020) Akincioglu, Sitki; Gokkaya, Hasan; Akincioglu, Gulsah; Karatas, Meltem A.Cryogenic treatment has been used in recent years to improve the performance of cutting tools. This study evaluated the machinability of a nickel-molybdenum-based super alloy using cryogenically treated (-80 celcius and -145 celcius) ceramic inserts under dry turning conditions. Three cutting speeds (350, 400, and 450 m/min), three feed rates (0.1, 0.2, and 0.3 mm/rev), and a 1-mm fixed cutting depth were used in the turning tests. Experiments were conducted using the Taguchi orthogonal array L(27)design. The factors affecting the surface roughness (Ra) were determined via analysis of variance. The effect of cryogenic treatment type (shallow and deep), cutting speed, and feed rate on surface roughness was investigated. Results of the analysis determined that the feed rate was the major parameter that affected surface roughness and that the deep cryogenic treatment was more effective. The regression analysis confirmed that the experimental results and the predicted values were within the 95% confidence interval. The most effective parameter affecting the surface roughness was feed rate at a contribution of 57.9%. The contribution of the cutting tool type to the surface roughness was 28.5%. The results obtained showed that the surface roughness can be optimized for turning the Hastelloy c22 super alloy with the Taguchi method.Öğe Wear response of non-asbestos brake pad composites reinforced with walnut shell dust(Springer, 2020) Akincioglu, Gulsah; Akincioglu, Sitki; Oktem, Hasan; Uygur, IlyasWith automobile numbers continuing to increase, competition among manufacturers of brake pads is also increasing along with the search for additives to serve as alternatives to the materials presently being used. In addition to the cost of the additives used, another important consideration in choosing materials is that they should be safe for the environment and human health. This study investigated the effect on braking performance of brake pads produced using walnut shell powder as a natural additive material. Two different types of brake pad samples were produced using 3.5 (2A) and 7% (2B) walnut shell dust in the contents. A commercial Clio brake tip was used as the reference (CO). The produced brake pads were subjected to thermal conductivity, friction wear, density, hardness and water and oil absorption tests and microstructure analysis. A Chase type device was used for wear friction tests, and the results were obtained according to SAE-J661(Brake Lining Quality Test Procedure) standards. The experimental data were compared with those of the commercial brake pads, and the performances of the natural additive brake pads were evaluated. The addition of walnut shell was shown to be compatible within the composition and exhibited a positive effect on the friction coefficient.
