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Öğe Mathematical modelling and optimization of cutting force, tool wear and surface roughness by using artificial neural network and response surface methodology in milling of Ti-6242S(Applied Sciences-Basel, 2017-10-15) Çelik, Yahya Hışman; Kılıçkap, Erol; Yardımeden, AhmetIn this paper, an experimental study was conducted to determine the effect of different cutting parameters such as cutting speed, feed rate, and depth of cut on cutting force, surface roughness, and tool wear in the milling of Ti-6242S alloy using the cemented carbide (WC) end mills with a 10 mm diameter. Data obtained from experiments were defined both Artificial Neural Network (ANN) and Response Surface Methodology (RSM). ANN trained network using Levenberg-Marquardt (LM) and weights were trained. On the other hand, the mathematical models in RSM were created applying Box Behnken design. Values obtained from the ANN and the RSM was found to be very close to the data obtained from experimental studies. The lowest cutting force and surface roughness were obtained at high cutting speeds and low feed rate and depth of cut. The minimum tool wear was obtained at low cutting speed, feed rate, and depth of cut.Öğe Investigation of experimental study of end milling of CFRP composite(De Gruyter, 2013-12-12) Çelik, Yahya Hışman; Kılıçkap, Erol; Yardımeden, AhmetCarbon fiber-reinforced plastic (CFRP) composites are materials that are difficult to machine due to the anisotropic and heterogeneous properties of the material and poor surface quality, which can be seen during the machining process. The machining of these materials causes delamination and surface roughness owing to excessive cutting forces. This causes the material not to be used. The reduction of damage and surface roughness is an important aspect for product quality. Therefore, the experimental study carried out on milling of CFRP composite material is of great importance. End milling tests were performed at CNC milling vertical machining center. In the experiments, parameters considered for the end milling of CFRP were cutting speed, feed rate, and flute number of end mill. The results showed that damage, surface roughness, and cutting forces were affected by cutting parameters and flute number of end mill. The best machining conditions were achieved at low feed rate and four-flute end mill.Öğe Investigation of mechanical characteristics of GFRP composites produced from chopped glass fber and application of taguchi methods to turning operations(SpringerLink, 2020-04-08) Çelik, Yahya Hışman; Türkan, CihatGlass fber-reinforced plastic (GFRP) composites take place in engineering materials owing to their low-weight and high-mechanical properties. In some cases, they need to be shaped by machining before using in industrial applications. However, when these composites are machined, many problems such as bad surface quality, rapid tool wear are encountered. Therefore, optimization of cutting parameters is essential to eliminate or minimize these problems. In this study, GFRP composites were produced by combining polyester matrix material with glass fbers (GF) having 6 mm, 6–12 mm, 12 mm fber length, and 20%, 25%, 30% fber ratio by weight. The tensile strengths of these composites were investigated. Turning tests were also performed with cutting speeds of 40, 80, and 120 m/min, feed rates of 0.1, 0.2 and 0.3 mm/rev, and depth of cut of 1, 2, and 3 mm, according to Taguchi L27 standard orthogonal array method. The efect of fber length and ratio, and cutting parameters on cutting forces and surface roughness were analyzed. As a result of the experiments, it was observed that the reinforced polymer matrix with GF provide to increase the tensile strength. The highest tensile strength was obtained as 55.95 MPa from the composite having a fber length of 12 mm and a fber ratio of 25%. Besides, the feed rate was determined as the most efective parameter among the all parameters on both cutting force and surface roughness. Therefore, the feed rate should be chosen low for lower cutting force and surface roughness values.Öğe Estimate of cutting forces and surface roughness in end milling of glass fiber reinforced plastic composites using fuzzy logic system(Walter de Gruyter, 2014-06-01) Çelik, Yahya Hışman; Kılıçkap, Erol; Yardımeden, AhmetMilling glass fiber reinforced plastic (GFRP) composite materials are problematic, owing to, e.g., nonhomogeneous and anisotropic properties and effects of plastic deformation. To reduce these problems, the effects of cutting speed, feed rate, and the number of flutes on surface roughness and of thrust forces occurring during the milling of GFRP composite materials were investigated by both experimental and fuzzy logic models. Experiments were performed at 30 m/min, 60 m/min, and 90 m/min cutting speeds, at 0.1 mm/rev, 0.15 mm/rev, and 0.2 mm/rev feed rates and 10 mm diameters in a cemented carbide end mill, which has two, three, and four flutes without cutting fluids. The values obtained from experiments were defined by a fuzzy logic model. A fuzzy logic model was employed to estimate the surface roughness and thrust forces for different cutting parameters. As a result of both the experimental study and the fuzzy logic model, while the minimum thrust force was obtained at low cutting speeds, and feed rates and a high number of flutes end mill, the best surface quality was obtained at low feed rates, high cutting speed, and number of flutes end mill.Öğe AL/SiC Kompozit malzemenin delinmesinde yüzey pürüzlülüğünün bulanık mantıkla modellenmesi(Dicle Üniversitesi, 2016) Çelik, Yahya Hışman; Yenigün, Burak; Kılıçkap, ErolBu çalışmada, sıkıştırma döküm yöntemiyle üretilmiş SiC takviyeli Al esaslı kompozit kullanılmıştır. Üretilen kompozit malzeme farklı uç açılarına sahip HSS takımlar kullanılarak; farklı delme parametrelerinde delme işlemine tabi tutulmuştur. Her bir delme işlemi için delme yüzeylerinin yüzey pürüzlülükleri ölçülmüştür. Elde edilen veriler bulanık mantığa uygulanarak yüzey pürüzlülüğünün modellenmesi yapılmıştır. Veriler incelendiğinde, en iyi yüzey pürüzlülüğü 90˚ uç açısına sahip takım kullanılarak 1500 dev/dak dönme devri ile 0.05 mm/dev ilerleme değerinde elde edilmiştir. En kötü yüzey pürüzlülüğü ise 118˚ uç açılı takımın 2000 dev/dak dönme devri ile 0.15 mm/dev ilerleme değerinde elde edilmiştir. Bulanık mantık kullanılarak elde edilen tahmini değerlerin deney sonuçlarına yakın değerler verdiği görülmüştürÖğe An experimental study on milling of natural fiber (jute)- reinforced polymer composites(SAGE, 2019-01-31) Çelik, Yahya Hışman; Kılıçkap, Erol; Kılıçkap, Ali İmranThe interest in materials having natural, environmentally friendly, renewable and low density/cost is increasing day by day due to sanctions imposed to reduce the emission rates, especially the Kyoto Protocol. In recent years, the use of environmentally friendly composites by using natural fibers such as flax, jute and sisal has increased in engineering applications. Milling operation has frequently been an important method of machining which can achieve the desired dimensions and tolerances for the plate-shaped parts. In this study, the effects of cutting parameters such as cutting speed and feed rate on cutting force, delamination factor and surface roughness in end milling of jute fiber-reinforced polymer composite plates with different orientation angle (0°/90°, 30°/−60° and ±45°) were examined by using the cemented carbide (WC) end mills (two, three and four number of flutes). Cutting force, deformation factor and surface roughness were found to be influenced by the feed rate and cutting speeds. In addition, increasing the number of the flutes of the cutting tools reduced the cutting force, delamination factor and surface roughness.Öğe Investigating the effects of cutting parameters on the hole quality in drilling the Ti-6Al-4V alloy(Materiali in Tehnologije, 2014-10) Çelik, Yahya HışmanIn this study, the effects of cutting parameters on the surface roughness, burr height, hole-diameter deviation, cutting temperature and structure of a chip formation were investigated during the drilling of the Ti-6Al-4V alloy. For this purpose, the Ti-6Al-4V alloy was drilled at different cutting parameters, longitudinally in the 10 mm depth with Ø = 10 mm high-speed-steel (HSS) drills, having 90°, 118°, 130° and 140° point angles on the CNC vertical machining centre. Experiments were carried out at the (12.5, 18.75 and 25) m/min cutting speeds and the (0.05, 0.1 and 0.15) mm/r feed rates without using the cutting fluid. As a result, as the feed rate and the drill-point angle were increased, the surface roughness increased as well; however, as the cutting speed increased, the surface roughness decreased. When the feed rate and drill-point angle increased, the burr height decreased. On the other hand, an increase in the cutting speed increased the burr height. In general, an increase in the feed rate and drill-point angle increased the hole diameters, and the hole diameters obtained were close to the nominal size when the cutting speed was increased.
