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Öğe Alüminyum alaşımlarının işlenmesinde kesme hızı ve talaş açısının yüzey pürüzlülüğü, yığıntı talaş ve yığıntı katmanı oluşumu üzerine etkisi(2015) Sekmen, Mustafa; Günay, Mustafa; Seker, UlviBu çalışmada, AA 2011 ve AA 7075 alüminyum alaşımlarının işlenmesinde, kesme parametrelerinin (takım talaş açısı ve kesme hızı) yüzey pürüzlülüğü üzerine etkileri incelenmiştir. Ayrıca, kesme parametreleri ile takım talaş yüzeyinde oluşan Yığıntı Katmanı (YK) ve Yığıntı Talaş (YT) arasındaki etkileşimler değerlendirilmiştir. İşleme deneylerinde, kesici takıma hem pozitif hem de negatif yönde talaş açısı verilerek talaş kaldırılmasını sağlayan bir deney düzeneği kullanılmıştır. Her iki alaşım için ortalama yüzey pürüzlülük (Ra) değerleri, talaş açısının büyük değerlerinde (15º ve 20º) düşük çıkarken, AA 7075 alaşımında özellikle talaş açısının küçük değerlerinde (0º ve -5º) oldukça yüksek çıkmıştır. Kesme deneylerinde kullanılan kaplamasız karbür kesici takımlar, metalografik yöntemlerle (SEM ve EDS analizi) incelenerek, talaş açısının ve alaşım içeriğinin YK ve YT oluşumu üzerindeki etkisi değerlendirilmiştir. AA 7075 alaşımında, AA 2011 alaşımına göre daha fazla YK ve YT oluşumu meydana gelmiştirÖğe Effect on Formations of Built-up Edge and Built-up Layer, Surface Roughness of Cutting Speed and Rake Angle in the Machining of Aluminum Alloys(Gazi Univ, 2015) Sekmen, Mustafa; Gunay, Mustafa; Seker, UlviIn this study, the effects on surface roughness of cutting parameters (tool rake angle and cutting speed) were investigated in the machining of AA 2011 and AA 7075 aluminum alloys. The interactions between the cutting parameters and Build-up edge (BUE), Built-up layer (BUL) formed on tool rake face were also evaluated the same machining processes. In the machining tests, the testing apparatus which allowing chip removal by giving rake angle in both positive and negative side to the cutting tool was used. The average surface roughness (Ra) values for both alloys were considerably high in especially small values of rake angle (0 degrees and -5 degrees) for AA 7075 alloy, while Ra values for both alloys have been low in larger values of rake angle (15 degrees ve 20 degrees). The effect of the formations BUE and BUL of the rake angle and the alloy content were evaluated by examining uncoated carbide cutting tools used in cutting experiments with metallographic methods (SEM and EDS analysis). Consequently, the formation of BUE and BUL for AA 7075 alloy has been greater than that of AA 2011 alloy.Öğe EXPERIMENTAL ANALYSIS AND THEORETICAL MODELLING OF CUTTING PARAMETERS IN THE DRILLING OF AISI H13 STEEL WITH COATED AND UNCOATED DRILLS(Univ Zagreb Fac Mechanical Engineering & Naval Architecture, 2018) Tekaut, Ismail; Demir, Halil; Seker, UlviIn this study, drillability experiments were carried out on the AISI H13 hot work steel which is difficult to machine. Uncoated and AlCrN-coated carbide drills, empty set14 mm, were used at 4 cutting speeds (60, 75, 90 and 108 m/min) and three different feed rates (0.15, 0.20 and 0.25 mm/rev). As a result of the experimental work, it was observed that an increase in the feed rate caused an increased on the thrust force in the workpiece machined with both the uncoated and coated drills. While an increase in the cutting speed caused the thrust force to increase in operations performed with uncoated drills, the increased cutting speed led to a decreased torque. In contrast, an increase in the cutting speed caused both the thrust force and the torque to decrease in the operations with coated drills. Stresses occurring on the drills were analyzed and a mathematical model was developed using the finite element method and the ANSYS Workbench package software.Öğe AN EXPERIMENTAL INVESTIGATION OF EFFECT OF CUTTING PARAMETERS ON CUTTING ZONE TEMPERATURE IN DRILLING(Gazi Univ, Fac Engineering Architecture, 2013) Yagmur, Selcuk; Acir, Adem; Seker, Ulvi; Gunay, MustafaDrilling is one of the most important machining processes in manufacturing industry. Recently, the work dealing with the problems encountered during drilling and their solution has been increased. Modelling of thermal and mechanical loads developed during drilling has also been increased. In this study, the drillability of AISI 1050 steel widely used in industrial applications will be investigated under various drilling types (hole type) cutting parameters (60, 75, 90 and 108 m/min cutting speed and 0.15, 0.20 and 0.25 mm/rev feed) and cutting tool type (uncoated and TiN/TiAl/TiCN coated solid carbide). Cutting temperatures developed along the drill rake face when drilling with coated and uncoated drill bits will be measured with the help of K type thermocouples inserted in the cooling channels of the drills. When the results of the experiments are evaluated, cutting temperature decreased with increasing feed and coating application significantly reduced cutting temperatures in the cutting zone. Coating application has provided significant benefits in the all parameters.Öğe The Influence of Chip Breaker Geometry on Tool Stresses in Turning(Assoc Mechanical Engineers Technicians Slovenia, 2011) Gurbuz, Huseyin; Kurt, Abdullah; Ciftci, Ibrahim; Seker, UlviIn this study, the influence of different chip breaker geometries on cutting forces and tool stresses developed during turning was investigated experimentally. For this purpose, turning tests in accordance with ISO 3685 were carried out on AISI 1050 steel using uncoated and coated cemented carbide cutting tools with different chip breaker geometries. The tests were carried out at different cutting parameters. The cutting forces were measured using a Kistler 9257B type dynamometer The effect of cutting force variation on tool stresses was analysed using finite element analysis software (ANSYS). The analyses results showed that the coated tools were subjected to higher stresses than the uncoated ones. However the stresses on the uncoated tools were found to be higher than those on the coated tools at the heavy cutting conditions. In addition, the chip breaker geometry was also found to result in variation in the stresses acting on the tools. (C)2011 Journal of Mechanical Engineering. All rights reserved.Öğe An Investigation into the Influences of Grain Size and Grinding Parameters on Surface Roughness and Grinding Forces when Grinding(Assoc Mechanical Engineers Technicians Slovenia, 2010) Demir, Halil; Gullu, Abdulkadir; Ciftci, Ibrahim; Seker, UlviThis study was carried out to investigate the effects of grain size on workpiece surface roughness and grinding forces when surface grinding AISI 1050 steel. A previously designed and constructed dynamometer was used to measure and record the forces developed during grinding. Grinding tests were carried out using different grinding wheels of different grains. Ground still ace roughness measurements were also carried out. The results showed that grain size significantly affected the grinding forces and surface roughness values. Increasing grain size and depth of cut increased the grinding forces and surface roughness values. For different grain sizes, depth of cuts of 0.01 and 0.02 mm did not result in any significant variations in the grinding forces but further increase in depth of cut led to variations of up to 50% in grinding forces. (C) 2010 Journal of Mechanical Engineering. All rights reserved.Öğe Investigation of chip-back temperature during machining depending on cutting parameters(Elsevier Sci Ltd, 2007) Korkut, Ihsan; Boy, Mehmet; Karacan, Ismail; Seker, UlviIn this study, measurement of the chip-back temperature developed during cutting was investigated using an embedded thermocouple into the cutting tool. AISI 1117 steel was used as the workpiece material and a K type thermocouple was used for the temperature measurement. The cutting tool used was uncoated and without chip braker and in the form of SCMW 12 M508-S217 according to ISO 1832. This cutting tool was fixed on a tool holder in the form of SSBCR 25 25 M12 and the side cutting edge angle during tests was 75 degrees as suggested in ISO 3685. The cutting tests were carried out on a Johnford TC35 CNC turning center. In selecting the cutting parameters, the reference values indicated in ISO 3685 were used. In order to locate the thermocouple on the cutting tool, a Flir Systems Therma Cam thermal camera was used. The results showed that increasing cutting speed, feed rate and depth of cut resulted in increase in the temperature at the back rake surface. However, cutting speed had the most influence on the temperature. (C) 2006 Elsevier Ltd. All rights reserved.Öğe The relationship of cutting force with hole quality in drilling process of AISI H13 steel(E D P Sciences, 2017) Tekaut, Ismail; Demir, Halil; Seker, UlviThe harmony of the drilling machine-cutting tool-work piece is very important for producing the machine part with the ideal dimensions. For this purpose in this study, the effect of cutting forces on hole quality (surface roughness, diameter deviation and circular deviation) was investigated by 14 mm diameter uncoated and (AlCrN monolayer) coated carbide drills for drilling AISI H13 hot work tool steel on vertical machining center. Four different cutting speeds (60, 75, 90 and 108 m / min) and three different feed rates (0.15, 0.20 and 0.25 mm / rev) were used in the experiments. Cutting forces have been found to be effective in improving hole quality. Better hole quality has obtained with coated drills than uncoated drills in experiments. It has been observed that coated drills have the effect of improving the hole quality due to the operation with less cutting force and better chip evacuation.
