Simulation on the Temperature Field of Bobbin Tool Friction Stir Welding of AA 2014 Aluminium Alloy

Liu, Xue Mei; Yao, Jiaxin; Cai, Yan; Meng, Hui; Zou, Zhengguang

doi:10.4028/www.scientific.net/amm.433-435.2091

Cited by 9 publications

(4 citation statements)

References 5 publications

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“…To date, several studies have been conducted to evaluate the temperature field [9,10], equipment [11], microstructures and mechanical properties [12][13][14][15] of bobbin tool friction stir welded joints in aluminum alloys. The microstructure and the mechanical properties are determined by the thermal cycle and the material flow behavior for the FSW [16].…”

Section: Introductionmentioning

confidence: 99%

Effect of Tool Rotational Speed on the Microstructure and Mechanical Properties of Bobbin Tool Friction Stir Welded 6082-T6 Aluminum Alloy

Sun

Gong

2019

Metals

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Samples of 6082-T6 aluminum alloy were welded by bobbin tool friction stir welding at different rotational speeds. The thermal cycles, microstructure, microhardness, and tensile properties of the specimens were investigated. The results show that the maximum temperature at the joint increases first and then decreases with increasing rotational speed, and the maximum temperature is 509 °C at 1000 r/min. The macromorphology of the cross-section of the joint is rectangular, and an ‘’S” line and gray-white texture can be observed. The stirred zone had much smaller equiaxed recrystallized grains. With increasing welding speed, the average grain size in the stirred zone region decreases. The microhardness distribution of the cross-section of all joints is W-shaped. When the rotational speed increases, the hardness of the heat-affected zone decreases gradually, and the hardness of the stirred zone increases. At 600 r/min, the strength is the lowest. The fracture location is between the stirred zone and the thermomechanically affected zone. When the rotational speed is increased, the fracture location is entirely located in the heat affected zone, and the fracture surface is dimple-like; the strength significantly increases and reaches a maximum at 800 r/min.

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Section: Introductionmentioning

confidence: 99%

Effect of Tool Rotational Speed on the Microstructure and Mechanical Properties of Bobbin Tool Friction Stir Welded 6082-T6 Aluminum Alloy

Sun

Gong

2019

Metals

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“…рис. [3][4][5]. При этом структуры выдавленного материала на входе инструмента и материала соединения являются практически идентичными, с наличием мелкодисперсного зерна и градиентным переходом к основному металлу через зону термомеханического влияния (см.…”

Section: результаты и обсужденияunclassified

“…Это позволяет получать сварные соединения различной конфигурации без использования подложки и снизить жесткость сварочного оборудования за счет отсутствия осевого усилия внедрения, характерного для обычной СТП [1,2]. Для BFSW также характерно снижение тепловых потерь и градиента температурного воздействия по толщине свариваемого материала [3,4]. В сравнении с CFSW это обеспечивает гомогенизацию структуры сварного соединения, снижение внутренних напряжений и градиента свойств его основных характерных зон.…”

Section: Introductionunclassified

Features of structure formation processes in AA2024 alloy joints formed by the friction stir welding with bobbin tool

Иванов¹,

Рубцов²,

Чумаевский³

et al. 2021

Metal Working and Material Science

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Introduction. One of friction stir welding types is the bobbin friction stir welding (BFSW) process, which allows to obtain welded joints in various configurations without using a substrate and axial embedding force, as well as to reduce heat loss and temperature gradient across the welded material thickness. This makes the BFSW process effective for welding aluminum alloys, which properties are determined by their structural-phase state. According to research data, the temperature and strain rate of the welded material have some value intervals in which strong defect-free joints are formed. At the same time, much less attention has been paid to the mechanisms of structure formation in the BFSW process. Therefore, to solve the problem of obtaining defect-free and strong welded joints by BFSW, an extended understanding of the basic mechanisms of structure formation in the welding process is required. The aim of this work is to research the mechanisms of structure formation in welded joint of AA2024 alloy obtained by bobbin tool friction stir welding with variation of the welding speed. Results and discussion. Weld formation conditions during BFSW process are determined by heat input into a welded material, its fragmentation and plastic flow around the welding tool, which depend on the ratio of tool rotation speed and tool travel speed. Mechanisms of joint formation are based on a combination of equally important processes of adhesive interaction in “tool-material” system and extrusion of metal into the region behind the welding tool. Combined with heat dissipation conditions and the configuration of the “tool-material” system, this leads to material extrusion from a welded joint and its decompaction. This results in formation of extended defects. Increasing in tool travel speed reduce the specific heat input, but in case of extended joints welding an amount of heat released in joint increases because of specific heat removal conditions. As a result, the conditions of adhesion interaction and extrusion processes change, which leads either to the growth of existing defects or to the formation of new ones. Taking into account the complexity of mechanisms of structure formation in joint obtained by BFSW, an obtaining of defect-free joints implies a necessary usage of various nondestructive testing methods in combination with an adaptive control of technological parameters directly in course of a welding process.

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“…Liu et al [36] simulated the temperature field of BT-FSW of 6-mm-thick 2014 aluminum alloy by using a coupled thermo-mechanical model in DEFORM-3D software. As Fig.…”

Section: Temperature Field and Flow Fieldmentioning

confidence: 99%

Research Progress of Bobbin Tool Friction Stir Welding of Aluminum Alloys: A Review

Wang

Zhao

Tang

2019

Acta Metall. Sin. (Engl. Lett.)

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Bobbin tool friction stir welding (BT-FSW) is a variant of conventional friction stir welding (FSW). It can be used to weld complex curvature structures and closed sections by adding an extra shoulder instead of a rigid backing anvil, which expands the potential application of FSW in aerospace, railway, automotive and marine industries. BT-FSW has some significant advantages over conventional FSW such as no root flaws, full weld penetration, low stiffness requirements for machines and fixtures, balanced heat input, lower distortion and thus has broad prospects for development. At present, there have been numerous research reports on BT-FSW, but its widespread use is still restricted due to various factors such as tool life, process stability, control complexity and implementation cost. In this paper, the domestic and foreign research progress of BT-FSW is reviewed from four aspects of bobbin tool design and classification, temperature field and flow field during welding, microstructure and mechanical properties of welded joints as well as industrial application, and then the possible research hotspots of BT-FSW in the future are pointed out. This paper mainly aims to help researchers have a comprehensive and in-depth understanding of BT-FSW.

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Simulation on the Temperature Field of Bobbin Tool Friction Stir Welding of AA 2014 Aluminium Alloy

Cited by 9 publications

References 5 publications

Effect of Tool Rotational Speed on the Microstructure and Mechanical Properties of Bobbin Tool Friction Stir Welded 6082-T6 Aluminum Alloy

Effect of Tool Rotational Speed on the Microstructure and Mechanical Properties of Bobbin Tool Friction Stir Welded 6082-T6 Aluminum Alloy

Features of structure formation processes in AA2024 alloy joints formed by the friction stir welding with bobbin tool

Research Progress of Bobbin Tool Friction Stir Welding of Aluminum Alloys: A Review

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