COMPARISON OF MECHANICAL AND MICROSTRUCTURES PROPERTIES OF DIFFERENT ALUMINUM ALLOYS JOINED WITH MIG AND FRICTION STIR WELDING METHODS
Yükleniyor...
Dosyalar
Tarih
2021-01-15
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Bu çalışmada, AA-5754 ile AA-6013 alüminyum alaşımı malzemeler sürtünme karıştırma (SKK) ve MIG kaynak yöntemleriyle birleştirilmiştir. Birleştirme işlemleri farklı kaynak parametreleri uygulanarak gerçekleştirilmiştir. SKK kaynak yönteminde farklı kaynak hızları, MIG kaynak yönteminde ise farklı kaynak hızları ve değişen kaynak akımları kullanılmıştır. Kaynak işlemi uygulanan numuneler öncelikle göz ile muayene edilmiş ardından numunelere mikro yapı çalışmaları uygulanmıştır. Kaynak metali üzerindeki ısı etkilerini değerlendirmek için SKK kaynak yönteminde termokupl ile sıcaklık ölçümü yapılmış, MIG yönteminde ise ısı girdisi hesaplanmıştır. Her iki yöntem ile birleştirilen numunelere sırasıyla sertlik, çekme, eğme ve yorulma testleri uygulanarak kaynaklı bağlantıların mekanik özellikleri belirlenmiştir. Yorulma testleri bu çalışmaya özgü tasarlanan, üretilen ve bu çalışmanın en önemli kazanımlarından olan eğme gerilmeli yorulma test cihazı kullanılarak yapılmıştır. Ayrıca çekme ve yorulma testleri sonucu meydana gelen kopma yüzeyleri SEM çalışmalarıyla incelenmiştir. Uygulanan tüm bu testlerle SKK ve MIG kaynak yöntemiyle elde edilen kaynaklı bağlantılar, mikroyapı-mekanik özellik ilişkileri bakımından kıyaslanmıştır. Numunelere uygulanan makro ve mikro yapı çalışmaları sonucunda her iki kaynak yöntemi için kullanılan uygun kaynak parametrelerinde daha iyi sonuçlar elde edilmiştir. Çekme ve yorulma testleri çalışmaları sonrasında, sonuçların birbiri ile son derece uyumlu olduğu bulunmuştur. Ayrıca, SKK ile uygun kaynak ilerleme hızında birleştirilen numunenin hem çekme dayanımının hem de yorulma ömrünün daha iyi olduğu belirlenmiştir.
In this study, AA-5754 and AA-6013 aluminum alloys were joined by friction stir welding (FSW) and MIG welding methods. Welding process was performed with using different welding parameters. Different weld speeds were used in FSW method while different weld speeds and variable weld currents were utilized in MIG method. The joined specimens were first inspected visually and then microstructure studies were implemented to the specimens. To determine the thermal effects on the weld metal, temperature was measured via thermocouple in FSW and heat input value was calculated in MIG method. Mechanical properties of the joints were specified by applying hardness, tensile, bending and fatigue tests to samples joined with both the two methods. The fatigue tests were performed using bending stress fatigue test machine which was designed and manufactured specifically for the study and this is the most important achievement of the study. Besides, fractured surfaces of the samples after tensile and fatigue tests were examined by SEM studies. With all the implement these tests, joints obtained both FSW and MIG methods were compared in terms of relationship their microstructure-mechanical properties. As a result of the macro and microstructure studies applied to the samples, better results were obtained with used appropriate welding parameters for both the two methods. After the tensile and fatigue tests, results were evaluated to be very compatible with each other. In addition, it was determined that both tensile strength and fatigue life of the sample joined with appropriate weld speed using FSW was better."
In this study, AA-5754 and AA-6013 aluminum alloys were joined by friction stir welding (FSW) and MIG welding methods. Welding process was performed with using different welding parameters. Different weld speeds were used in FSW method while different weld speeds and variable weld currents were utilized in MIG method. The joined specimens were first inspected visually and then microstructure studies were implemented to the specimens. To determine the thermal effects on the weld metal, temperature was measured via thermocouple in FSW and heat input value was calculated in MIG method. Mechanical properties of the joints were specified by applying hardness, tensile, bending and fatigue tests to samples joined with both the two methods. The fatigue tests were performed using bending stress fatigue test machine which was designed and manufactured specifically for the study and this is the most important achievement of the study. Besides, fractured surfaces of the samples after tensile and fatigue tests were examined by SEM studies. With all the implement these tests, joints obtained both FSW and MIG methods were compared in terms of relationship their microstructure-mechanical properties. As a result of the macro and microstructure studies applied to the samples, better results were obtained with used appropriate welding parameters for both the two methods. After the tensile and fatigue tests, results were evaluated to be very compatible with each other. In addition, it was determined that both tensile strength and fatigue life of the sample joined with appropriate weld speed using FSW was better."
Açıklama
Anahtar Kelimeler
Alüminyum alaşımları, sürtünme karıştırma kaynağı, MIG kaynağı ve yorulma testi., Aluminum alloys, friction stir welding, MIG welding and fatigue test.
