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Öğe 3b metal yazıcı kullanılarak mig-mag kaynak yöntemi ile tamironarım kaynak uygulamasına bir örnek(2018) Ayan, Yusuf; Sarı, Ertan; Kahraman, NizamettinBu çalışmada; MIG-MAG kaynak ünitesi, 3B metal yazıcıya monte edilerek MAG kaynak yöntemi ile bir tamironarım kaynak işlemi gerçekleştirilmiştir. Bu amaç için kırılmış kabul edilen bir makine dişlisi kullanılmıştır.Kırılmış dişlinin tasarımı bilgisayar destekli ortamda tasarlanıp lazer kesme işlemi ile üretilmiştir. Daha sonra kırıkolan dişli parçaları hassas bir şekilde 3B metal yazıcının tablasına sabitlenmiştir. 3B yazıcıyla metal malzeme veplastik malzeme biriktirme işlemleri arasında önemli bir fark bulunmaktadır. 3B yazıcılarda plastik malzemekullanıldığında çalışma sıcaklığı yaklaşık 190-200 °C arasında iken metal malzeme ergitilirken çalışma sıcaklığıyaklaşık 3000-4000 °C’ye ulaşır. Bu çalışma sıcaklığının çok yüksek olması 3 boyutlu metal yazıcının çalışmasınıolumsuz yönde etkilemektedir. Bu nedenle çalışmada metal doldurma işlemini gerçekleştirmek için 3 boyutlumetal yazıcıda önemli uyarlamalar yapılmıştır. Kırık dişli parçalarının tamir edilecek bölgesini doldurma işlemiMAG kaynağı ile ilk ikisi parçanın üst tarafından diğer ikisi ise alt tarafından olacak şekilde dört pasodagerçekleştirilmiştir.Öğe Carbon dioxide (CO2) laser machine design, production and test studies for marking and cutting processes(Gazi Univ, 2024) Kole, Alper; Ayan, Yusuf; Kahraman, NizamettinSince its early development, lasers had big impact in today's technology advancement by facilitating our daily life. The manufacturing industry has taken the largest share of laser technology, and it has become a preferred technology in many manufacturing applications. Almost all material types can be processed with the laser and laser technology is widely used in industry for marking, engraving, and cutting processes. This article discusses designing and manufacturing of a low-budget CO2 laser machine, for marking, engraving, and cutting applications. All major components of the machine including resonator, optical train, cutting head and control systems have been discussed in detail for interested readers to implement a similar system. The resonator on the machine was designed and manufactured to allow repeated gas filling which is a major benefit for economical and extended service life as compared to similar commercially available systems. The machine has been described from initial material list and manufacturing process involved, all the way to the final aforementioned application examples for rubber, wood, and plastic materials. The laser machine system is currently installed in Karabuk Univesity's manufacturing engineering department and used for undergraduate teaching and learning. Furthermore, it is sufficient capacity for use in medium-sized operations in advertising, hobby, forest products, textile, leather, and small-scale engineering works.Öğe Characterization of the weld zone of Grade AH36 steel ship plate joined at the real marine conditions through underwater welding(Gazi Univ, Fac Engineering Architecture, 2020) Colak, Zahit; Ayan, Yusuf; Kahraman, NizamettinIn this study, Grade AH36 steel ship plate was joined at both the atmospheric and real underwater conditions at ascending different depths through shielded metal arc welding process. The isolated E6013 rutile electrode was used in welding process. The welded specimens firstly subjected to visual inspection and this was followed by radiographic test. Bending and impact toughness tests were also carried out in order to determine the mechanical properties of the welded joints. Microstructural examines were performed to observe the structural transformation and hardness test was also conducted on the weld zones. Non-destructive test results showed that the specimens joined underwater had weld defect such as slag remains on the weld surface and between the pass, gas porosities, grooves and the lack of penetration. According to the bending test results, when the difference of water depth increased, the tests resulted in adversely at some angles due to defects like remains, gas porosities etc. on the weld metal. With respect to impact toughness tests, the specimens welded at atmospheric conditions presented better toughness than the others. The maximum hardness value was measured from the weld metal and this was followed by the heat affected zone (HAZ) and base metal sequentially. Microstructure evolutions showed that structures of the weld metals were dendritic, rolled structure of the base metal in the HAZ was destroyed and partial grains growth was seen in this section.Öğe Development of a New High Strength Alloy from Low Alloy Steel Wire by Innovative Additional Cold Wire Feeding Used in Wire Arc Additive Manufacturing(Mary Ann Liebert, Inc, 2024) Saribiyik, Ziya; Ayan, Yusuf; Kahraman, NizamettinOne of the most important features of the wire arc additive manufacturing (WAAM) is the ability to produce new structures from different materials. Thanks to the ease of application of the WAAM, more than one same or different material can be involved in the production process. Thus, WAAM has the potential to produce new material structures from raw wire metals with different chemical contents. In this study, it was aimed to produce a new alloy structure using WAAM. A novel cold wire feeding technique with an external system and gas metal arc welding (GMAW) process was implemented for the fabricating of a new alloy part. In the fabrication process, two different grades and ratios of ER70S-6 (90%) and 316LSi (10%) steel wires were used and melted simultaneously. The new alloy structure was successfully fabricated, and significant changes were found in the microstructure and tensile strength because of Cr and Ni elements transferred from the secondary wire (316LSi). In the microstructure of the new alloy, structures such as acicular ferrite, martensite, and bainite were observed. As a result of the different fabrication approach applied, a significant increase in tensile strength was found. The tensile strength of the new alloy structure exceeded 1000 MPa and almost 100% increase in strength was observed compared to single-material structures. In addition, the ductility of the produced structure was found to be sufficient. The study showed that new alloys with improved mechanical properties can be produced with the cold wire feeding + GMAW approach.Öğe Fabrication and characterization of a new high-strength alloy via WAAM using GMAW+cold wire feeding(Elsevier, 2024-12-01) Ayan, YusufThe demand for high-strength steels has continued to increase in various fields of industry due to the advancement in technology. The wire arc additive manufacturing (WAAM) enables the fabrication of high-strength structures from different materials by controlling the raw wire in layers. This study focuses on the fabrication of high-strength steel by WAAM using the gas metal arc welding + cold wire feeding (GMAW + CWF) technique. A new alloy was formed by simultaneously adding 316LSi stainless steel from the CWF to the low alloyed ER70S-6 steel from the GMAW torch. In this way, three different new alloyed structures were produced with varied 316LSi ratios ranging from 10 %, 20 % and 25 % respectively. Besides, their metallurgical and mechanical properties were compared with each other and with single material WAAMed structures. In the macrostructure examinations, no defects due to the mixture of both materials were found and both materials melted properly to create the new alloy. Due to the alloying elements transferred from 316LSi, the microstructure of the new material parts were completely changed compared to the single material WAAMed components and bainite and martensite phases were found in the new alloys. The hardness increased significantly compared to the single-material WAAMed structures and increased up to 139 % and 84 % compared to the single-material WAAMed ER70S-6 and 316LSi, respectively. The tensile strength showed a great improvement and reached almost 1200 MPa, increased by 142 % compared to the single-material WAAMed structure. The fabricated new alloys have the potential to be a candidate material for industries that use high-strength steel.Öğe Fabrication and characterization of functionally graded material (FGM) structure containing two dissimilar steels (ER70S-6 and 308LSi) by wire arc additive manufacturing (WAAM)(Elsevier, 2022) Ayan, Yusuf; Kahraman, NizamettinFunctionally graded materials (FGM) are components that can provide different material properties in a single structure. It is sometimes required to exhibit locally different material behaviours from parts used for various purposes in the industry. In such requirements, the use of FGM structures emerges as a solution. The fabrication of FGM structures with traditional manufacturing methods is generally complicated and sometimes not possible. However, the additive manufacturing (AM) technique, which is the topic of many applications and research today, has emerged as a superior manufacturing method compared to traditional methods in fabrication FGM structures, thanks to its advantages. Fabrication in the form of layers with the AM allows the fabrication of layers with varying material properties. This study was carried out on the fabrication of FGM structures by the wire arc additive manufacturing (WAAM) method, which is one of the metal AM techniques. Low alloy steel (ER70S-6) and austenitic stainless steel (308LSi) metal wires are used in FGM structures. The FGM structure was success-fully fabricated by the WAAM method. Hardness, tensile, and fatigue tests were applied to determine the me-chanical properties of the part. In addition, XRD analysis and microstructure studies were carried out to understand the metallurgical properties. As a result of the mechanical tests, no defects were observed in the FGM interfaces, and an increase of up to 46% was observed in the tensile strength compared to the single-material fabrication. In hardness measurements and microstructure studies, it has been observed that the FGM struc-ture exhibits different properties according to the changing layers. It has been concluded that the fatigue limit of the FGM part in the horizontal direction is 25% higher than in the vertical direction.Öğe Fabrication and Fatigue Properties of Dissimilar Steel Functionally Graded Material Structure Through Wire Arc Additive Manufacturing(Springer, 2023) Ayan, Yusuf; Kahraman, NizamettinFunctionally graded materials (FGM) are structures that can provide different material properties together. To produce these structures, the additive manufacturing method has been used and preferred. In this study, an FGM structure was fabricated by wire arc additive manufacturing (WAAM) process using low-alloy ER70S-6 and austenitic stainless steel 308LSi metal wires. The FGM structure was characterized by tensile, fatigue, hardness tests, and microstructure examinations. As a result of the applied tests, it was found that the FGM structure has strong interfacial strength. In addition, no formations or defects that could reduce the strength of the FGM part were observed at the interface and in the regions close to the interface. The sides of the FGM part containing the base material could reflect their characteristic material properties. FGM part, whose properties can be changed partially, has been successfully fabricated.Öğe FARKLI MALZEME KATMANLI ÜRÜNLERİN TEL ARK EKLEMELİ İMALATI(2022-03) Ayan, YusufFonksiyonel derecelendirilmiş malzemeler (FDM) farklı malzeme özelliklerini tek bir yapıda sağlayabilen üretimlerdir. Endüstride farklı amaçlar için kullanılan parçalardan kimi zaman bölgesel olarak farklı malzeme davranışlarını sergilemesi istenebilmektedir. Bu tür ihtiyaçlarda FDM yapılarının kullanılması bir çözüm olarak ortaya çıkmaktadır. FDM yapılarının geleneksel imalat yöntemleriyle üretilmesi ise genel olarak zor olup, bazen mümkün olamamaktadır. Ancak günümüzde birçok kullanıma ve araştırmalara konu olan eklemeli imalat (Eİ) tekniği, sunduğu avantajlar sayesinde FDM yapılarının üretimi noktasında geleneksel yöntemlere göre üstün bir imalat yöntemi olmuştur. Eİ yöntemiyle katman şeklinde üretim yapılabilmesi, katman özellikleri değiştirilebilen yapıların imalatına izin vermektedir. Bu çalışma metal Eİ tekniklerinden biri olan tel ark eklemeli imalat (TAEİ) yöntemiyle FDM yapılarının üretilmesi üzerine gerçekleşmiştir. FDM yapılarında iki farklı kimyasal bileşime sahip düşük alaşımlı çelik (SG2) ile östenitik paslanmaz çelik (308LSi) metal teller kullanılmıştır. TAEİ işlemleri çalışmalar kapsamında özel olarak tasarlanan ve gelişmiş özellikler kazandırılan bir tezgahın üretimiyle gerçekleştirilmiştir. Malzeme yığma işlemlerinde MIG/MAG kaynak yöntemi tercih edilmiştir. Üretim işlemleri temel olarak iki farklı düzende uygulanmıştır. Bunlardan ilki sadece tek besleyici tel ile üretilen tek malzemeli yapıları diğeri ise farklı iki tel kullanımıyla FDM yapılı üretimleri kapsamaktadır. Toplamda 4 farklı üretim gerçekleştirilmiş, bunlardan 1’incisi tamamı sadece SG2, 2’ncisi ise tamamı sadece 308LSi tel malzemesinden oluşacak şekilde üretilmiştir. 3’üncüsü yarısı SG2 diğer yarısı 308LSi malzemesinden oluşacak şekilde üretilmiştir. 4’üncüsü SG2 ve 308LSi malzemelerinin her katmanda sırasıyla değiştirilmesi şeklinde üretilmiştir. 4 farklı üretim grubunun elde edilmesinden sonra tek malzemeli ve FDM yapılarının özelliklerini belirlemek için birçok mekanik ve metalürjik testler uygulanmıştır. Mekanik özellikleri belirlemede, sertlik, çekme, yorulma, eğme ve çentik darbe testleri, metalurjik özellikler için ise makro/mikro yapı çalışmaları yapılmıştır. Tüm üretim gruplarına uygulanan deneysel çalışmalarda elde edilen bulgular birbiriyle mukayese edilmiştir. Deneysel çalışmalar sonucunda FDM üretimlerinin hiçbirinde üretim hatasıyla karşılaşılmamış ve FDM yapılarında bulunan iki farklı malzemeden dolayı meydana gelen ara yüzeyler tüm testlerden başarılı olmuştur. FDM üretimiyle tek malzemeli üretimlere göre üstün mekanik özellikler sağlanmıştır. FDM yapılarında tek malzemeli üretimlerle kıyaslandığında; çekme dayanımında % 50’ye, yorulma dayanımında ise % 34’e varan artış tespit edilmiştir. Çalışmalar sonucunda TAEİ yöntemiyle özellikleri üstün FDM yapılarının üretilebileceği görülmüştür.Öğe Gap bridging in laser welding of EN AW 5083 with different joint configurations via beam oscillation and filler wire(Springer London Ltd, 2024) Yetil, Kenan Kaan; Colombo, Daniele; Ayan, Yusuf; Demir, Ali GokhanThe extended use of laser welding in the industry requires a less sensitive process in terms of geometrical tolerances of the joint edges. As the industrial availability of laser systems increases, the demand to use laser welding technology possibly with parts coming from less precise production steps is increasing. Gap formation is often caused by the edge quality of the parts coming from previous manufacturing steps such as sheet forming. Al alloy sheets deformed to box-shaped 3D forms often require welded joints on the edges in lap, but, and corner joint configurations. These joints are hard to carry out by laser welding due to the large gap formation caused by the tolerances of the deformation processes involved. Laser welding of Al alloys is already challenging in the absence of gap formation, while these joint configurations have been not feasible with a stationary beam due to incomplete fusion and defect formation. Laser welding with beam oscillation and wire feeding can improve the weldability of these joints. The oscillating motion of the high-intensity beam can achieve a deep weld together with a wider seam. Combined with wire feeding, the process can close gaps in the butt, lap, and corner joint configurations. On the other hand, the added oscillation and wire-related parameters require extending the experimental space, which requires a methodological study to identify feasible conditions. Accordingly, this work proposes a methodological approach to identify and set laser welding process parameters with beam oscillation and wire feeding for an EN AW 5083. Process parameters were initially studied using a simple analytical model that depicts the beam trajectory. Bead-on-plate tests were conducted to assess beam size, power, and weld speed ranges. Lap, butt, and corner joint conditions with a 0.5-mm gap were welded with high quality by manipulating the laser power, oscillation amplitude, and wire feed rate. The results show that welding speeds could be maintained as high as 55 mm/s with complete filling of gaps of up to 0.5 mm, eliminating the surface undercuts and achieving weld widths in the order of 2.5 mm. Moreover the results show the possibility control the depth of the welds from 3 mm to full-penetration conditions.Öğe İnce cidarlı silindirik parçaların tornalanmasında bağlama kuvvetlerinin etkisinin incelenmesi(Karabük Üniversitesi, 2017) Ayan, Yusuf; Çiftçi, İbrahimBu çalışmada ince cidarlı bilezik şeklindeki bir parçaya belirlenen bağlama kuvvetleri uygulanarak bilezikte meydana gelen elastik deformasyonlar sonlu elemanlar analizi yöntemiyle incelenmiştir. Çalışmada dış çapı 60 mm, iç çapı 40 mm bilezik şeklinde bir parça kullanılmıştır. 3, 4, 6 ayaklı bağlama sistemleri modellenerek bağlama kuvvetlerinin etkisiyle bilezik şeklindeki parçada meydana gelen değişimler incelenmiştir. 3 farklı bağlama sisteminin her birinde, belirlenen 5 farklı bağlama kuvveti uygulanmıştır. Sonuç olarak 3 ayaklı sistemde bağlama kuvvetlerinin uygulanmasıyla parçanın iç yüzeyinde üçgen, 4 ayaklı sistemde dörtgen, 6 ayaklı sistemde altıgen bir biçim oluşmuştur. Uygulanan bağlama kuvvetlerinin büyüklüklerinin artmasıyla parçada oluşan elastik deformasyon miktarları da orantılı olarak artmıştır. Uygulanan aynı bağlama kuvvetlerinde ayak sayısının artmasıyla elastik deformasyon miktarlarında azalma görülmüştür. Elastik deformasyon miktarlarının ayakların olduğu bölgelerde en büyük, iki ayak arasındaki bölgelerde ise en küçük olduğu görülmüştür.Öğe Investigation of tensile and fatigue properties of an austenitic stainless steel part fabricated by WAAM(Elsevier Science Sa, 2024) Ayan, Yusuf; Kahraman, NizamettinAustenitic stainless steels are used in many industrial applications and the use of components produced from this material by the wire arc additive manufacturing (WAAM) method has gained interest. Since damage of metallic parts generally occurs due to fatigue, it is necessary to understand their fatigue properties. This study focused on the determination of tensile and fatigue properties of an austenitic stainless steel structure produced by WAAM. For this purpose, a medium-sized part was fabricated using 308LSi metallic wire and gas metal arc welding (GMAW) technique. Hardness tests and microstructure examinations were also performed on the part. In the tensile tests, it was found that the strength and ductility of the vertical and horizontal samples were different. However, the fatigue test results of horizontal and vertical specimens were very similar. The average fatigue limit was found to be 195 MPa, and the fatigue life of the sample reached 107 without any macro damage. As a result of the hardness tests, the average hardness was calculated as 197 HV0.5. In the microstructure studies, different ferrite formations were observed in the austenite matrix on the bottom, middle and upper zones. The changes in microstructure were mostly attributed to the exposure of multiple layers to different heating and cooling rates during WAAM.Öğe Microstructure and mechanical properties of aluminum alloys AA5754 and AA6013 joined by GMAW (Gas metal arc welding) method(Pamukkale Univ, 2020) Mercan, Emine; Ayan, Yusuf; Kahraman, NizamettinThe use of aluminum alloys in industry have been increased in due to their excellent low weight, corrosion resistance also other good features. Different aluminum alloys are joined with together when need of a structure presents different physical or mechanical properties with together. In this study, different aluminum alloys AA5754 and AA6013 joined by GMAW (gas metal arc welding) method under different welding parameters. After that, three-point bending test was carried out and notch impact test was performed to determine toughness behavior of the joints. In addition, the weld zone is characterized with hardness test and microstructure studies. While the welded samples joined with convenient parameters were bended 180 degrees, the cracks and fractures were occurred on the fusion line boundary of some samples due to unsuitable parameters. According to impact toughness test results, the highest toughness value was obtained from the HAZ (Heat affected zone) of AA5754. Besides, toughness values evaluated from the HAZ of AA6013 on the joints and weld metal were nearly same. With respect to hardness test results, the maximum hardness value was measured at the HAZ of AA6013 and this was followed by the weld metal and the HAZ of AA5754 sequentially. From the point of microstructure inspections, structures of all the weld metals were dendritic.Öğe Sg2 düşük alaşımlı ilave metal kullanılarak tel ark eklemeli imalat yöntemi ile üretilen silindirik parçanın mekanik özelliklerinin araştırılması(2024) Altun, Kürsat Uygar; Çaglar, Ercan; Ayan, Yusuf; Kahraman, NizamettinBu çalışmada, son yıllarda kullanım alanları ve önemi giderek artan eklemeli imalat tekniklerinden tel ark eklemeli imalat yöntemi (TAEİ) kullanılmıştır. Çalışmada düşük alaşımlı çelik olan SG2 gazaltı kaynak teliyle silindir şeklinde parça üretimi yapılmıştır. Çalışmanın amacı standart olarak temin edilemeyen boruların istenilen ölçülerde tel ark eklemeli imalat yöntemiyle üretilmesidir. Üretim işlemlerinde MIG-MAG kaynak yöntemi kullanılmıştır. Üretilen parçadan alınan numunelere mekanik ve metalürjik testler uygulanmıştır. Mekanik özellikleri belirlemede çekme ve sertlik testleri, metalürjik özellikleri belirlemede ise makro/mikro yapı çalışmaları yapılmıştır. Çekme testi 3 farklı numune grubuna (direk alındığı haliyle, sadece frezelenmiş numune, frezelenmiş+standart çekme numunesi) uygulanmıştır. Çekme testinde numune grubuna göre değişen sonuçlar elde edilmiştir. Numunelerin mikroyapılarında ağırlıklı olarak poligonal ferrit yapısı gözlemlenmiştir. Üretilen numuneden ölçülen ortalama sertlik değerinin yaklaşık 166 HV olarak ölçülmüştür.Öğe A study on the effects of test frequency on the fatigue life of pla parts manufactured by additive manufacturing(2024) Ayan, YusufFatigue tests of materials require longer time than most other mechanical tests when the enitre process is considered. One of the most critical factors affecting the test time is the test frequency. In this study, fatigue tests at different test frequencies were applied to the PLA parts produced by the additive manufacturing (AM) technique, and the effects of test frequency were investigated. In the fatigue tests, four different stress levels were applied, and the tests were carried out at four different frequencies: 2 Hz, 4 Hz, 6 Hz, and 8 Hz. The fatigue life of the samples changed according to the applied stress levels at varying test frequencies. There was an approximately 44% decrease in the fatigue life found with increasing test frequency at the 1st stress level Fatigue life showed an increasing trend at and after the 3rd stress level. At the 4th stress level, fatigue life increased by 45% when the test frequency was changed from 2 Hz to 8 Hz. In general, after a specific fatigue life, it was observed that increasing test frequency tended to increase the fatigue life.Öğe Weld morphology and mechanical performance of marine structural steel welded underwater in a real marine environment(Springer London Ltd, 2020) Colak, Zahit; Ayan, Yusuf; Kahraman, NizamettinGrade AH36 ship steel plate, frequently used in offshore applications, was joined underwater by shielded metal arc welding (SMAW) using two different types of electrodes (E6013 and E7014). The ship steel plate was also joined under atmospheric conditions in order to compare both joints in terms of mechanical and metallurgical properties. The E6013 rutile electrode was isolated by wrapping before use, and the underwater welding process was carried out at a depth of 8 m under the sea. The joints were first subjected to visual inspection and then liquid penetrant, ultrasonic, and radiographic tests were performed. In order to determine the mechanical properties of the joints, tensile, bending, and impact toughness tests were also carried out. In addition to the microhardness test on the weld zones, microstructural examination was also performed on the joints. As a result of the nondestructive tests, weld defects like slag remaining between the passes, gas porosities, burn-through, and lack of penetration were seen on the joints welded underwater with the two different electrodes. The study determined that these defects had significantly influenced the mechanical properties and width of the weld zone of the joints.
