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The additive manufacturing method offers a number of advantages such as rapid prototyping, design flexibility and unique part production. However, compared to traditional production methods, the production volume is limited. Therefore, to meet large-volume production demands, additive manufacturing is not as effective as traditional methods. In order to overcome this disadvantage, scientists are conducting research on the assembly of parts produced by additive manufacturing method. This study focuses on investigating the MIG (Metal Inert Gas) weldability of AlSi10Mg SLM (Selective Laser Melting) plate to AlSi10Mg SLM plate and subsequently optimizing the welding parameters for welding zone hardness and tensile strength. The most suitable parameters obtained in the hardness optimization of the weld zone were determined as 20.6 V, 120 A, 5356 (AlMg5). The most suitable parameters for tensile strength optimization were determined as 20.6 V, 110 A and 4047 (AlSi12). In addition to all these, 4047 filler material is thought to be the most suitable weld filler material for this study, as it provides the best tensile strength performance, offers acceptable weld zone hardness and is relatively easily accessible in the market. [ABSTRACT FROM AUTHOR]

Savunma sanayisinin zırhlı araçları için geliştirilen düşük alaşımlı yüksek mukavemetli zırh çeliklerinin ark kaynak teknolojisi uygulamaları metalurjik bilgi ve deneyim isteyen zor uygulamalardır. Bu çeliklerin yüksek karbon eşdeğeri ve yüksek mukavemeti sağlayan martenzitik mikroyapıları nedeniyle kaynak proseslerinde güçlüklerle karşılaşılmaktadır. Seçilecek kaynak telinin yüksek süneklilik kapasitesi olan östenitik ya da yüksek mukavemetli olan ferritik yapıda olması kaynak metalinin sahip olacağı mekanik özellikleri ve kaynaklı bağlantının balistik özelliklerini belirlemektedir. Bu seçimler, doğası gereği kaynak parametrelerini ve proses adımlarını da farklılaştırmaktadır. Bu çalışmada; zırh çeliklerinin sınıflandırılması ile kaynak yönteminin, kaynak konfigürasyonun, kaynak metalinin, ısı girdisinin, ısıl işlem uygulamalarının ve gerçekleşen ısıl çevrimlerden dolayı elde edilen mikroyapısal değişimlerin mekanik ve balistik özelliklere etkileri tartışılmıştır.

The applications of arc welding technology for low-alloy high-strength armor steels developed for defense industry are challenging processes that require metallurgical knowledge and expertise. The high-carbon equivalent and martensitic microstructures, which provide high strength in these steels, lead to difficulties during the welding processes. The choice of welding wire with high ductility, such as austenitic, or high-strength ferritic structures, determines the mechanical properties of weld metal and the ballistic characteristics of the welded joint. These choices naturally lead to variations in welding parameters and process steps. In this study, the classification of armor steels, welding methods, welding configurations, weld metal properties, heat input, heat treatment, and the effects of microstructural changes resulting from heat cycles on mechanical and ballistic properties have been discussed. [ABSTRACT FROM AUTHOR]

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Gazi Üniversitesi Fen Bilimleri Dergisi Part C: Tasarım ve Teknoloji is the property of Gazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

QStE 420 TM quality steel sheet plate materials, which are widely used in sectors such as defense industry and automotive industry, are made of fine-grained and micro-alloyed structure and are joined separately using the shielded metal arc welding method with the help of basic type rod electrodes with 3 different chemical compositions (E11018-G H4, E7018-1 H4R and E7018 H8 AWS coded). Mechanical and metallurgical effects on the welding zone (base material, heat-affected zone and weld metal) formed after the melting of electrodes with different chemical compositions in specified parameters; the samples were examined by applying macrostructure and microstructure examinations, as well as mechanical tests by applying tensile, bending, notch impact and hardness tests. As a result of the tests, the mechanical and metallurgical effects occurring in the weld zone were investigated by performing macro-micro structure examinations and applying tensile, bending, notch impact and hardness tests. In these tests, the fulfillment of the expected mechanical and metallurgical properties of the welded joints obtained from the basic electrodes of different compositions was examined in terms of weldability. Based on the comparative test results, the most appropriate results are; It was obtained from test samples that were combined in 4 passes with the electrode coded E7018 H8, at an average current intensity of 190 A, an arc voltage of 33 V and an average welding speed of 2.93 mm/second. [ABSTRACT FROM AUTHOR]

316L austenitic stainless steels were produced by powder metallurgy method at 600 MPa and 700 MPa pressing pressures in this study. The weldability of these steels was investigated by applying the resistance spot welding method. The microstructure of the welded sample was analyzed in detail with optical microscope. In addition, the hardness values of the base metal, heat-affected zone and weld metal regions formed as a result of resistance spot welding process were measured. Consequently, it was observed that the base metal microstructure was mainly composed of austenite phase. Due to the high heat occurring in resistance spot welding process, weld metal mainly consisted of delta ferrite phase in the austenite matrix. Hardness values increased from base metal to weld metal. Also, the hardness values measured in different welding regions of the sample obtained at 700 MPa pressing pressure were found to be higher than the sample obtained at 600 MPa pressing pressure. [ABSTRACT FROM AUTHOR]

In this study, the weldability of magnesium alloy anode bars (AZ63) by friction welding method was investigated. Friction welding was used to join magnesium alloy bars for this work. Friction welds were carried out at 1800 rpm, 2000 rpm and 2200 rpm. Microstructure analyses and mechanical tests were performed after the welding process to determine the effects of the welds. SEM pictures of the microstructure of the welded joints were acquired for this purpose. For mechanical strengths, hardness measurement and tensile tests were carried out. As a result of the tensile test, the highest tensile force was obtained as 2969.68 N in the sample combined with 2000 rpm. The magnesium alloy anode bars may be welded without any problems using the friction welding method, according to the experiment results. However, as a result of SEM and mechanical tests, it was seen that the best coupling was obtained from the 2000 rpm parameter. [ABSTRACT FROM AUTHOR]

This study focused on optimization of different electrode tip types (Conical round, Flat R3, Flat R6, Flat conical) and welding current parameters to obtain the ideal tensile shear strength of resistance spot welded DP600 steel. Welding processes were carried out at 5 and 7 kA welding currents for each of the 4 different tip types. Experimental results showed that welding current is the most important variable affecting tensile shear strength. As the welding current increased, the tensile shear strength increased. It has been determined that there is a linear relationship between the nugget diameter value and the tensile shear strength. The highest tensile shear strength values were obtained with flat 3 mm radius electrode tips and the lowest with conical round tip electrodes. [ABSTRACT FROM AUTHOR]

Solidification cracking is a concern for welding magnesium (Mg) alloys. An index, the maximum 'dT/d(fS)1/2', was used with the thermodynamic software Pandat to make solidification cracking susceptibility predictions for AZ-Mg arc welds which have the main alloying elements of aluminum and zinc in the magnesium matrix. The effect of AZ101 magnesium filler on reducing crack susceptibility of commercially available AZ31, AZ61 and AZ91 Mg alloys was investigated with the crack susceptibility index. The filler metal AZ101 Mg alloy was found effective to reduce the susceptibility of all the three AZ-Mg alloys to solidification cracking. The influence of the amount of aluminum and zinc in the AZ-Mg alloys on the crack susceptibility was predicted using the cracking index and Pandat based on Scheil solidification model. The predictions based on the index were compared to the experimental crack susceptibility data of the AZ-Mg alloys, and it was seen that the general trend of both predictions and the reported data was consistent with each other. The predictions were explained in the light of the criterion proposed for solidification cracking. [ABSTRACT FROM AUTHOR]

İstenen özelliğe sahip malzemeler üretebilmek için farklı malzemeler bir arada kullanılabilir. Bu araştırmanın temel amacı elektrik ark tekniği ile birleştirilen AISI 316 ve AISI 4140 kaynaklarının kaynaklanabilirliğini ve mekanik özelliklerini incelemektir. Mekanik özellikler, çekme ve darbe çentik testleri ile belirlenmiştir. Kritik noktalar ve Charpy enerjisi değerleri sırasıyla yük uzama eğrileri ve darbe testi yardımıyla belirlenmiştir. Mekanik özelliklere ait bilgiler, kaynak noktaları ve kaynak noktalarına yakın noktalardaki sertlik değerleri belirlenmek suretiyle elde edilmiştir. Mikroyapı incelemeleri, optik mikroskop kullanılarak gerçekleştirilmiştir. Elde edilen sonuçlar, AISI 316 ve AISI 4140 çeliklerinin elektrik ark kaynağı ile başarılı bir şekilde birleştirilebileceğini ve mühendislik işlemlerinde güvenle kullanılabileceğini göstermektedir.

Bu çalışmada, östenitik paslanmaz çelik (AISI 304) ve düşük karbonlu çelik (S235JR) malzemenin gaz metal ark kaynak yöntemi kullanılarak farklı akım-voltaj (kaynak enerjisi) değerleri ve tel besleme hızlarında kaynak edilebilirliği araştırılmıştır. Kaynaklı numunelere çekme testi ve sertlik deneyleri yapılarak birleştirilen malzemelerin mekanik özellikleri incelenmiş, sonuçlar Taguchi ve varyans analizi (ANOVA) metodu kullanılarak değerlendirilmiştir. Ayrıca kaynak bölgesinin mikroyapısı incelenerek, ısı tesiri altındaki bölgenin (ITAB) sertlik davranışı açıklanmaya çalışılmıştır. Çekme deneyi sonuçlarına göre deformasyon, kaynak bölgesi dışında, düşük karbonlu çelik bölgesinde meydana gelmiştir. Sertlik değerlerinin analizinde enerji girdisi artışının sertliği azalttığı, tel besleme hızındaki artışın ise sertliği artırdığı belirlenmiştir. Mikroyapı çalışmaları sonucunda, kaynak bölgesinde tane büyümesinin meydana geldiği tespit edilmiştir. ANOVA sonuçlarına göre kaynak bölgesi enerji miktarı ve tel besleme hızı parametreleri kaynak bölgesinin sertlik davranışını %70 oranında açıklayabilmektedir.

Copyright of SDU Journal of Engineering Sciences & Design / Mühendislik Bilimleri ve Tasarım Dergisi is the property of Journal of Engineering Sciences & Design and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Welding process is often used in joining of similar and dissimilar steel sheets in the automotive industry. In these joining applications, resistance spot welding is the most commonly used welding method. There are on average around 3000 or 6000 spot welds in a car. The advantages of resistance spot welding are as follows: it is a relative clean and environmentally friendly process, suitable for automation and readily applicable, does not require filler metal, produce open flame that can cause accidents and injury, and require an expert operator. This study provides information about manuel and robotic spot welding applications which are performed on the vehicle body. It focusses on different types of spot welding electrodes used, their cooling methods, maintenance and life-cycles. In addition, spot welding optimization which is used for increasing weld quality during mass production is mentioned. [ABSTRACT FROM AUTHOR]

Alüminyum birim ağırlık başına yüksek mukavemet özelliği, güvenirliği, uzun ömürlü oluşu, tasarım esnekliği, ısıl performansı, yüksek geri kazanım oranı gibi özellikleri nedeniyle kullanım alanları her geçen gün artmaktadır. Alüminyum ve alaşımlarının kaynak edilebilme özelliklerinin ve kaynaklı parçaların mekanik özelliklerindeki iyileşme kullanım alanını daha da genişletecektir. Bu çalışmada, seçilen Etial 7 alüminyum malzemesine % 1 bakır ve % 2, 3, 4, 5 silisyum ilavesi yapılarak elde edilen parçalar Metal İnert Gaz (MİG) kaynağı ile kaynatıldı. Kaynaklı parçalardan standartlara uygun numuneler hazırlandı. Bu numuneler üzerinde yapılan sertlik, çekme ve çentik darbe deneyleri ile kaynak dikişinin mekanik özellikleri incelendi.

The world energy demand is expected to grow, thus natural gas will grow fastest in 20 10's and will overtake coal as the world's second-largest energy source and consequently gas consumption would double in the next twenty years. Handling and storage of natural gas is only rational by low temperature liquefaction. By liquefying natural gas at -163°C, its volume is reduced by a factor of more than 600 times thus making handling and storage easier and more economical. The need for weldable 5%-9%Ni steels for cryogenic applications remaining ductile and crack resistant at low temperatures and having high strength would increase in our country as well in the coming years. For these reasons, the weldability of these steels should be well understood. This paper will discuss the production, metallurgical and mechanical properties and weldability of the 5%-9% Ni steels that are expected to be increasingly used in LNG storage. [ABSTRACT FROM AUTHOR]

Heat treatable, high strength, weldable 7020-T651 alloy is used due to its high fatigue strength and high yield strength in welded military structures. This alloy has satisfactory arc weldability with filler metal 5356 and after welding, mechanical properties equivalent to those of the parent metal in the T4 temper can be achieved. However, it shows a strong sensitivity to exfoliation corrosion in the heat affected zone, on either side of the welding bead once it has been incorporated into a welded structure. In order to successfully use this material in welded design suitable precaution must be taken against exfoliation corrosion. Step aging after welding will provide an appreciable measure of protection against exfoliation corrosion [1,2]. It is the aim of this study to see the effect of heat treatment after welding, on exfoliation corrosion resistance and mechanical strength of EN AW 7020-T651 aluminium alloy. [ABSTRACT FROM AUTHOR]

Copyright of Teknoloji is the property of Engineering Science & Technology, an International Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)