Effect of welding parameters on microstructure and mechanical properties of AA7075/AA5182 alloys joined by TIG and MIG welding methods

Abstract

In this study, V and X welding grooves were opened to the forehead positions of the AA5182 and AA7075 aluminum alloy pairs and these alloy pairs were joined with tungsten inert gas (TIG) and metal inert gas (MIG) methods. Three different welding currents were used in joints. Gas flow rates of 12 and 17 l/min at the TIG welding and wire feed rates of 38 and 45 cm/min at MIG welding were selected. The effect of the welding grooves, welding current, gas flow rate and wire feed rate on microstructure and mechanical properties were investigated. Microstructures of welding zones were analyzed by an optical microscope and a scanning electron microscope (SEM). Vickers hardness of these zones was also measured. In addition, tensile and fatigue tests were carried out. Fracture mechanisms of failed specimens were conducted after the tensile tests were examined by using SEM. The highest hardness, tensile and fatigue strengths were obtained from the alloy pairs joined by opening X welding groove with TIG welding method. These values were 89 HV, 262.87 MPa, and 131.5 MPa, respectively. Similarly, the lowest tensile and fatigue strengths were obtained from the alloy pairs joined by opening V welding groove in the TIG welding method. These values were, respectively, 94.48 MPa and 19.1 MPa. However, the minimum hardness value was measured as 58 HV from the alloy pairs joined by opening V welding groove with MIG welding methods. In addition, it was observed on the fracture surfaces that the grain distributions and mechanisms differed depending on the welding methods, welding groove, and welding parameters.

Sürtünme Kaynağı İle AA7075 Alüminyum Alaşımının Kaynak Edilebilirliğinin Araştırılması

“…Çetkin vd., TIG ve MIG kaynağı ile birleştirilen AA7075/AA5182 alaşımlarının mikroyapı ve mekanik özelliklerine kaynak parametrelerinin etkisini incelemişlerdir. İyi bir kaynak kalitesi için her iki kaynak yönteminin de uygulanabileceğini tek koşulun optimum kaynak parametrelerinin belirlenmesi olduğunu ifade etmişlerdir [11]. Sameer ve Anil, AZ91 magnezyum alaşımı ve AA 6082-T6 alüminyum alaşımının sürtünme karıştırma kaynaklı farklı bağlantılarının mekanik ve metalürjik özelliklerini incelemiştir.…”

Sürtünme Kaynağı İle Birleştirilen AISI 1020/RAMOR 500 Çelik Çiftinin Mikroyapı Ve Mekanik Özelliklerinin İncelenmesi

“…Endüstri ve savunma sanayisindeki hızlı gelişim ile birlikte kullanılan metalik malzemelerin birleştirilme işlemi de bir o kadar önem kazanmıştır. Geleneksel ergitme kaynak yöntemleriyle birleştirilen metalik malzemelerde çeşitli sorunlar ortaya çıkabilmektedir [1]. Yeni ve özellikli malzemelerden olan zırh çelikleri geleneksel ergitme kaynak yöntemleri ile birleştirildiğinde bazı metalürjik problemler ortaya çıkmaktadır.…”

ANN Based Estimation of Geometry of Bead-on-Plate in Pulsed Gas Tungsten Arc Welding

“…Welding defects can be reduced by adjusting the parameters suitably [10]. The microstructure of the welded joint is also affected by the selection of welding parameters [11]. In addition to the choice of welding parameters, use of various types of flux material influences the characteristics of welded joint [12].…”