Evaluating alloy-718 machinability values modelling by using response surface methodology

188-194With the development of the manufacturing industry, machining parameters and material processing efficiency are important due to cost, sustainability, and other parameters, which are determining factors for usage width, material choice, and production rate. Machinability and optimization are among the scientists' and industry workers' timely objectives, guiding the manufacturing industries. Thus, the study and analysis of parameters such as surface roughness, tool wear, and force application in superalloy machining would be beneficial in various fields of the manufacturing industry. In this work, RSM (surface response method) modelling and analysis of relationship Fx, Fy, Fz forces between surface roughness of Inconel-718 material, which is a very unique alloy in terms of corrosion resistance, high-temperature elevation, and fatigue values, is examined. From this work, it was found that an experimental design was prepared using the Taguchi method, and the required number of measurements and parameter values were determined with a small number of experiments. Then, the most ideal values were determined using the Response Surface Methodology and ANOVA method to determine the best parameter levels after the surface roughness and cutting forces measurements

CNC tezgahlarında dönel elemanların işlenmesinde yapay sinir ağı ile kesici takımın seçimi

CNC TEZGAHLARDA DÖNEL ELEMANLARIN İŞLENMESİNDE YAPAY SİNİR AĞI İLE KESİCİ TAKIM ŞEÇİMİ Bilgisayar teknolojisinin gelişmesi sayesinde bütün alanlarda aktif olarak bu teknolojiden yararlanılmaya başlanılmıştır. Talaşlı imalat endüstrisinde geçmişte konvensiyonel tezgahlar kullanılarak üretim yapılmakta idi, günümüzde ise gelişen bilgisayar teknolojisi ile birlikte CNC (Computer Numerical Control) Tezgahlar geniş bir şekilde kullanılmaya başlanılmıştır. Ülkemizdede kısa bir süre içerisinde bu teknoloji aktif olarak, sanayide kullanılmaya başlanılmış olup, en küçük işletmelerde bile bu tezgahlar kullanılarak üretim yapılmaktadır. Büyük işletmelerde aynı tip seri üretim yapıldığı için çok kısa zamanda program ve takım değişikliğine pek gidilmez. Fakat seri imalat yapmayan işletmelerde, ürün değişkenliğinde ötürü sık sık program ve takım değişikliği yapılmak zorundadır. Bundan dolayı üretim programının hızlı ve hatasız bir şekilde yapıldığı talaş kaldırma, takımın optimum şekilde seçimi de önem kazanmıştır. Bu takım seçme işlemi yapılırken takım deposundaki takımlar çok iyi tanınmalı, her iş parçası değiştiğinde mümkün olduğu kadar yeni takım sipariş edilmesi yerine eldeki takımlar verimli şekilde kullanılmalıdır. CNC tezgahlarda üretime başlamak için; CNC programının hazırlığı, uygun takımların seçimi ve tarete yerleştirilmesi ve buna ilave olarak, parçanın uygun aparat veya aynaya emniyetli bir şekilde bağlanması gerekir. CNC Torna tezgahlarında kullanılan programlar CAD/CAM yazılımları vasıtasıyla ISO kodunda üretilir. Burada kesmede kullanılacak takımın seçilebilmesi için iyi bir takım bilgisine ihtiyaç vardır. Bu bilgiye sahip olmak uzun bir deneyim ve mesleki bilgiyi gerektirmektedir. Bu çalışmada, DXF formatındaki parça profili elde edildikten sonra eldeki takım kütüphanesi, tezgah özelliklerini ve kesilecek malzeme bilgilerini dikkate alarak takım seçme işlemini Yapay Sinir Ağları Yöntemi kullanılarak otomatik olarak yapmaktadır. Ayrıca, bu çalışmada mevcut olan CNC programı okunarak buradan işlenecek olan iş parçası profili oluşturulmaktadır. Bu oluşturulan parça profili esas alınarak, yine Yapay Sinir Ağları yöntemiyle uygun takımlar otomatik olarak seçilmektedir. Seçilen takımların listelenmesi ve resimlerinin gösterilmesi sayesinde takım dolabına gitmeden takım tanınmakta ve böylece zaman kaybı olmadan eldeki takımlardan en uygun olanı program sayesinde seçilmektedir. Haziran, 2003 Ayhan ETYEMEZ ABSTRACT TOOL SELECTION AT MACHINING OF ROTATIONAL PARTS' WITH ARTIFICIAL NEURAL NETWORK ON CNC MACHINES In chip removal industry, production used to be made by conventional machine tools. Whereas today, CNC machines have been widely used with the help of this developed computer - technology. In a short time, this technology has started to be used in our country's production industry and even in small companies; manufacturing is carried out by using CNC Machines. Because mass production is carried out in big companies, there is no need to change frequently. On the other hand, the companies in which mass production is not carried out, program and tool change should be done frequently because of the diversification of the production. There fore, the selection of the optimal tool has become important in chip removal process where the program is carried out fast and without deficiency. During the tool selection process the tools in the tool stock should be well known and the tools on hand should be used efficiently instead of ordering a new tool at each time a work piece is changed. In order to start the operation in CNC machine, the preparation of CNC, the selection and positioning of appropriate tools should be done and the tool should be securely tightened on a chuck or a device. Programs used in CNC Lathe Machines are produced with the aid of CAD/CAM in ISO code. In order to able to select the tool that is going to be used in cutting process, it is necessary to have a good knowledge about tools. To acquire this knowledge on should have experience and professional knowledge. In this thesis, automatic tool selection process is completed by using Artificial Neural Network Method from the tool library after recognizing work piece profile from the DXF format together with the necessary data about machine tools specification and work piece materials. In addition, work piece profile is created by using CNC program in this study. This work piece machining profile is taken as a reference for selecting appropriate tools

Optimization of the effects of wire EDM parameters on tolerances

In this study, the effects of cutting parameters on the dimensions and shape tolerances of components were investigated. Nine pieces of cubes with dimensions 10 x 10 mm were cut by using DIN 1.2316 (M303 extra) plastic mold steel. A Sumitomo Denko SBG-type wire with a 0.25 mm diameter was used. Table feed rate, pulse-on time and pulse-off time were used as machining parameters. The pulse-off time adjustment, maximum current of the main power supply, auxiliary power supply network, main power supply voltage, servo reference voltage, wire feed rate, wire tension and dielectric fluid circulation pressure were kept constant during the experiments. Three-dimensional coordinate measuring equipment was used to measure the tolerances of dimensions and shapes. Wire electrical discharge machining (EDM) parameters were optimized by using the Taguchi optimization technique. In order to optimize the wire electrical discharge process, the gray relational analysis (GRA) optimization method was used. The optimal machinability of DIN 1.2316 plastic mold steel for the wire electrical discharge process was successfully determined in this study. With GRA, the obtained optimum values were 9 mm/min table feed rate, 8 ms pulse-on time and 8 mu s pulse-off time

Quality in turning of Inconel X-750 superalloy

This study has been conducted to analyse the effects of turning the Inconel X-750 superalloy, which is a member of a nickel-based superalloy family that is frequently preferred in the aerospace and nuclear energy industries in particular, under minimum quantity lubrication (MQL), cryogenic liquid nitrogen (LN2 ) and carbon dioxide gas (CO2) cooling/lubrication conditions, with different cutting speeds (V-c = 65, 95, 125 and 155 m/min) and constant feed rate (f=0.1 mm/revolution) and cutting depth (a =0.5 mm) parameters, on the processability of Inconel X-750, hence on the surface integrity. In this context, the results obtained from the tests have been comparatively examined through surface roughness, tool wear and chip formation. Comparison results show that the cryogenic carbon dioxide method has generally provided the best surface roughness and tool wear values. The MQL method has provided the best chip formation

Examination of the effects of abrasive powder amount added to the minimum quantity-lubrication system on the cutting process

In machining operations, the cutting process is negatively affected due to the high temperature occurring between the cutting tool and the workpiece. The heat generated in the environment should be removed from the cutting point with a chip. In this study, the surface roughness of the processed surfaces and the changes in cutting forces depending on the abrasive powder added to the minimum-quantity-lubrication (MQL) system and cutting speed were examined. In the experiments, 1.2379 cold-work tool steel hardened to 59 HRC hardness was used; a cubic boron nitride (BN) cutting insert, which is resistant to turning operations at high hardness, was chosen as the cutting insert; and aluminum oxide (Al2O3) nanoparticles were used as abrasive powder. When the experiment results were examined, the best average surface roughness obtained was 0.888 mm in the experiment where the cutting speed applied was 160 m/min and volumetric nanofluid concentration applied was 4%. When the resultant cutting forces were examined, it was observed that the change in the abrasive powder amount did not have as much effect on the resultant cutting forces as surface roughness did. Therefore, it was revealed that the nanofluid-doped MQL system applications are needed to increase surface quality with a lubrication effect rather than a cooling effect

Drilling performance of functionally graded composite: Comparison with glass and carbon/epoxy composites

WOS:000415983500016Functionally graded composite (FGC) materials are categorized as advanced materials that display different thermal and mechanical responses compared with well-known composites, such as carbon fiber or glass fiber-reinforced composites. This paper presents the experimental results for the drilling of three materials, namely glass/epoxy, carbon/epoxy, and FGC material. FGC was compared with carbon and glass/epoxy composites in terms of thrust force, delamination factor, diameter of hole, and roundness during drilling. This study illustrated that the drilling performance of FGC is considerably more complicated than that of more common composite materials, such as glass/epoxy and carbon/epoxy. Delamination factor at the exit of hole during drilling of FGC was mainly affected by the material placed at the exit of the hole. The proposed cutting parameters and drill geometries to minimize the occurrence of delamination during drilling of carbon/epoxy and glass/epoxy apparently does not meet the expectation in drilling FGC