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The paper is concerned with the effect of punch angle (0 degrees, 4 degrees, 8 degrees, 16 degrees), sheet thickness (0.8, 2 mm), and punch speed (25, 37.5 mm / min) on the force formation and noise in the blanking of DP600 dual-phase steel sheet. The blanking experiments were carried out in a modular blanking die. The blanking force and noise variables were obtained simultaneously during the blanking using a load cell and noise measuring device, respectively. It was determined that the blanking force significantly decreased with an increasing punch angle, while noise formation decreased. The increase in the punch speed slightly increased the amount of noise while it did not affect the blanking force significantly.

Bu çalışmada, AISI 316L çeliğin işlenmesinde kesici takım formlarının ve kesme parametrelerinin yüzey bütünlüğü üzerine etkileri deneysel olarak araştırılmıştır. Kesme deneylerinde, PVD kaplı MM ve MF formlu sinterlenmiş karbür kesici takımlar ve PSBNR 2525M12 standardında takım tutucu kullanılmıştır. Kesme parametreleri dört farklı kesme hızı, üç farklı ilerleme miktarı ve iki farklı kesme derinliği şeklinde belirlenmiştir. Yüzey bütünlüğü; yüzey pürüzlülüğü, kalıntı gerilmeler, mikrosertlik ve mikroyapı analizleri açısından değerlendirilmiştir. Bütün kesme şartlarında, kesme derinliği ve ilerleme miktarı arttığında yüzey bütünlüğünün kötüleştiği, buna karşın kesme hızındaki artışla birlikte yüzey bütünlüğünün iyileştiği görülmüştür. Kesici takım formları karşılaştırıldığında en iyi yüzey bütünlüğü sonuçları MF formlu kesici takımlarla, en kötü yüzey bütünlüğü sonuçları ise MM formlu kesici takımlarla elde edilmiştir. Talaş açısı artıkça yüzey bütünlüğü iyileşmiştir. En kötü yüzey bütünlüğü kesme hızı 200 m/dak, ilerleme miktarı 0,1 mm/dev ve kesme derinliği 1,25 mm olduğunda, en iyi yüzey bütünlüğü ise kesme hızı 125 m/dak, ilerleme miktarı 0,3 mm/dev ve kesme derinliği 2,5 mm olduğunda elde edilmiştir., In this study, the effects of the cutting tool forms and cutting parameters on the surface integrity were experimentally investigated in machining of AISI 316L steel. In cutting tests, PVD coated MM and MF formed cutting tools and tool holder suitable for these cutting tools were used. Cutting parameters were determined by using three different feed rate, four different cutting speeds and two different depths of cut. The surface integrity was evaluated in terms of surface roughness, residual stress, microhardness and microstructure analysis. In all cutting conditions, it was observed that the surface integrity worsened when the depth of cut and feed rate increased, whereas the surface integrity improved when the cutting speed increased. When the cutting tool forms were compared, the best surface integrity results were obtained with the cutting tools which had MF form, while the worst surface integrity results were obtained by the cutting tools which had MM form. As rake angle increased, surface integrity improved. The worst surface integrity was obtained with the cutting speed 125 m/min, feed rate 0.3 mm/rev and depth of cut 2.5 mm, while the best surface integrity was obtained with the cutting speed 200 m/min, feed rate 0.1 mm/rev and depth of cut 1.25 mm.

Bu çalışmada, taşıtlardakisüspansiyon sistemlerinin bir parçası olan hava süspansiyon körüğünün üretimtipinin ürün kalite özellikleri üzerine etkisi incelenmiştir. Üretilenkörüklerin ilgili standartlar göz önünde bulundurularak fiziksel ve mekaniközellikleri belirlenmiştir. Üretilen körüğün mekanik performanslarınınbelirlenmesine yönelik çalışma kapsamında Patlatma Test Makinesi,Taşıma-Genişleme ve Ömür Test Makinesi kullanılmıştır. İmal edilen havasüspansiyon körüklerinin mekanik özelliklerini incelemek amacıyla patlatma,taşıma, genişleme ve ömür testleri gerçekleştirilmiştir. Testler sonrasında,körüğe ait patlatma basıncı, taşıma yükü değeri, tekrarlı yükleme durumundakuvvet değerlerindeki değişimler belirlenmiştir. Ayrıca, körüğün taşıma yükü veyatay yer değiştirme değerleri altında boyutsal değişimleri tespit edilmiştir., In this study, the effect of the production type ofair suspension on the product quality characteristics has been investigated;which are part of the suspension systems in vehicle. The physical andmechanical properties of fabricated air spring bellows were determined takinginto account the relevant standards. In scope of the work for determiningmechanical performance of fabricated air spring bellows, The Explode TestMachine, The Conveying-Widening and Life Test Machines were used. For analyzingthe mechanical properties of manufactured air spring bellows; explode,conveying-widening and life tests has been effectuated. After the tests,explode pressure of air spring bellows, value of carrying load, the changes ofthe value of force in case of repeatedly loading were determined. Moreover, thevalue of loading capacity of the air spring bellows and the dimensional changeswithin the horizontal displacement values were determined.&nbsp

In this study, the effects of cutting insert rake face forms and cutting parameters on the surface integrity in machining of AISI 316 L steel were investigated experimentally. The cutting forces occur during chip removal, surface roughness values on the machined surfaces with residual stresses on machined workpiece were measured, and metallurgical structure (microhardness and microstructural variations) of the surface layers formed as a result of machining were evaluated. The surface integrity was evaluated in terms of surface roughness, residual stress, microhardness, and microstructure analysis. In experiments, the best surface integrity results were obtained by cutting tools having QM form, and the worst surface integrity results were obtained by cutting tools having MR form. Under all these cutting conditions, it was observed that the surface integrity worsened when depth of cut and cutting feed were increased; however, the surface integrity improved when cutting speed was increased. In terms of cutting parameters, the best surface integrity was obtained with cutting speed 200 m/min, cutting feed 0.1 mm/rev, and depth of cut 1.25 mm; on the other hand, the worst surface integrity was obtained with cutting speed 125 m/min, cutting feed 0.3 mm/rev, and depth of cut 2.5 mm.

Residual stresses play an important role in the performance of materials and the components produced from them. All manufacturing processes introduce residual stresses. These stresses can have a positive effect, for example by increasing the fatigue limit in the case of compressive surface residual stresses. Layer removal by electrochemical machining (ECM) can be used for measurement of the residual stresses in the PM parts. The device removed the layers by aid of electrochemical machining for this purpose is designed and developed. The device setup for residual stress measurement is based to the changes on deformation quantity. Since ECM is a non-mechanical metal removal process, ECM is capable of machining any electrically-conductive material with attendant high removal rates, regardless of mechanical properties. In particular, the removal rate in ECM is independent of the hardness, the porosity and toughness of the PM parts being machined. The micro constituents in PM steels resulting from different processing routes exhibit different thermal and mechanical behavior. This will lead to the formation of residual stresses around these micro constituents. Here we give the results of the first work carried out on PM steels in relation to residual stress measurements by the electro-chemical layer removal technique. The device works as follows. As a layer of thickness is removed, a certain amount of stress is removed from the sample. Equilibrium is violated and the sample deforms elastically to compensate for the stress removed. This elastic deformation in the sample is measured by the linear displacement gauge. This gauge pushes on the end of sample and deformation is recorded by this gage. The linear gauge send a signal to a display and then to the data converter. As simultaneous, this signal sent to the computer from the data converter for further calculations by RS 232.

The characteristics of residual stresses occurring in PM steel based nickel (FLN2-4405) was investigated. Residual stresses were measured by electrochemical layer removal technique. The values and distributions of residual stresses occurring in PM steel processed under various densities (6.8, 7.05, 7.2 and 7.4 g/cm(3)) and heat treatment conditions (sintered at 2050 degrees F, sintered at 2300 degrees F, quenching-tempered, and sinter-hardened) were determined. In most of the experiments, tensile residual stresses were recorded on the surface of the samples. The residual stress distribution on the surface of the PM steels was found to be affected by the heat treatment conditions and density. The maximum values of residual stresses on the surface showed sinter hardened condition and a density of 7.4 g/cm(3). The minimum level of recorded tensile residual stresses are 150 MPa and its maximum level is 370 MPa.

ARCAKLIOGLU, Erol/0000-0001-8073-5207 WOS: 000248783400006 This paper presents a new approach based on artificial neural networks (ANNs) to determine the residual stresses in PM steel based nickel (FLN2-4405). This study consists of two cases: (i) The experimental analysis: The measurements of residual stresses were carried out by electrochemical layer removal technique. The values and distributions of residual stresses occurring in PM steel processed under various densities (6.8, 7.05, 7.2 and 7.4 g/cm(3)) and heat treatment conditions (sintered at 2050 degrees F, sintered at 2300 degrees F, quenching-tempered, and sinter-hardened) were determined. In most of the experiments, tensile residual stresses were recorded in surface of samples. The residual stress distribution on the surface of the PM steels is affected by the heat treatment conditions and density. Maximum values of residual stresses on the surface were observed sinter hardened condition and 7.4 g/cm(3) density. (ii) The mathematical modeling analysis: The use of ANN has been proposed to determine the residual stresses based on heat treatment conditions and densities in PM steel using results of experimental analysis. The back propagation learning algorithm with two different variants and logistic sigmoid transfer function were used in the network. In order to train the neural network, limited experimental measurements were used as training and test data. The best fitting training data set was obtained with four and five neurons in the hidden layer, which made it possible to predict residual stress with accuracy at least as good as that of the experimental error, over the whole experimental range. After training, it was found the R 2 values are 0.999244, 0.999025, 0.999664 and 0.999322 for sintered at 2050 degrees F, sintered at 2300 degrees F, quenching-tempered, and sinter-hardened, respectively. Similarly, these values for testing data are 0.998354, 0.99706, 0.999607 and 0.999205, respectively. As seen from the results of mathematical modeling, the calculated residual stresses are obviously within acceptable uncertainties. (c) 2006 Elsevier Ltd. All rights reserved.

Metastable beta-titanium alloys are especially favourable as implant materials because this type of Ti alloy containing beta stabilising elements such as Nb, Zr and Ta has an excellent combination of low modulus, high strength, corrosion resistance and biocompatibility. A low elastic modulus reduces the risk of stress shielding and associated bone resorption. The difficulty of producing complex shapes of these alloys by conventional methods for reasonable costs makes Metal Injection Moulding (MIM) attractive. In this work, the results of using MIM to process successfully Ti-24Nb-4Zr-8Sn alloy powder are presented. Specimens with relative density up to 97.6% have been produced using a feedstock based on wax-polymer binder. Microstructure observations reveal a pure beta microstructure with TixC precipitates along the grain boundaries. The carbides form due to reaction of titanium with binder residuals and deteriorate the plastic behaviour. However, the specimens exhibit an ultimate tensile strength within the range from 655 to 720 MPa and a plastic elongation ranging between 2% and 9% in dependence on sintering parameters. The lowest Young's modulus is about 54 GPa and this value is about 50% lower than that of CP Ti and Ti-6Al-4V. (C) 2014 Elsevier B.V. All rights reserved.

The objective of this study is to obtain the cutting force components on the threading insert. The cutting force data used in the analysis are measured by a three-dimensional dynamic force dynamometer. The AISI 4140 and AISI 4340 low alloy steels are selected for the experiment on the threading and the side cut turning. The inserts used for testing is the TiAlN coated and uncoated grades. LT22NR35ISO type insert is used in the experiment. During the experiments, no cutting fluid and a constant spindle speed is used. The thread pitch and the depth of cut were kept fixed at 3.5 mm and 0.05 mm for the radial feed per pass, respectively. The study emphasizes on the effects on the workpiece material and the cutting tool grade of the cutting force components that occur during the threading. Also, these results are compared with the findings that are obtained during the side cut turning. It is determined that the measured primary cutting and radial forces during the threading are approximately three times bigger than those during the side cut turning, although feed forces during the threading are approximately 30 times lower compared with the side cut turning. The TiAlN coated WC/Co grade shows the best performance with respect to the cutting force components. The specific cutting forces are determined in order to understand the interference of chips that occur during the threading. With the increase in the cumulative radial feed, the corresponding specific cutting forces become higher. It is reasoned that the difference in the specific cutting forces results from the alteration of the interference of the flowing chips. The specific cutting forces decrease in the beginning of the threading and then increases with the cumulative radial feed. The results show that the interference of the chip flow influences the threading force components to a very large extent. [DOI: 10.1115/1.4001867]