Experimental investigation on friction stir welding of dissimilar aluminium alloys

2021 ◽  
pp. 095440892110086
Author(s):  
Shubham Verma ◽  
Joy P Misra
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloys ◽  
Research Work ◽  
Weight Percent ◽  
Nugget Zone ◽  
Friction Stir ◽  
Metallurgical Properties ◽  
Metallurgical Analysis ◽  
Strength Material ◽  
Onion Ring

In current research work, dissimilar aluminium alloys such as AA5083, AA6081, AA6082, and AA7039 are butt joined by employing friction stir welding (FSW). The present study explores the effect of material positions of aluminium alloys (i.e., advancing side (AS) and retreating side (RS)) on the mechanical and metallurgical properties of FS welded dissimilar aluminium joints. The performance characteristics of the present study are analyzed in terms of mechanical and metallurgical properties. It is concluded that maximum strength is obtained for all the joints in which higher strength aluminium alloy is placed on the AS ((i.e., 386 MPa for AA7039-AA5083, 343 MPa for AA7039-AA6082, 320 MPa for AA5083-AA6082, and 225 MPa for AA6082-Aa6061). Furthermore, two types of macrostructures (i.e., banded and an onion ring) are observed at the nugget zone (NZ) of all the welded joints during metallurgical analysis. Besides this, energy-dispersive X-ray spectroscopy (EDS) analysis at NZ of FSW joints is also carried out to find out the chemical composition at NZ. It is observed that the key element of AS material is high er in weight percent as compared to RS at NZ. Moreover, tensile fractured surface locations are also analyzed to understand the process better. It is witnessed that most joints are fractured at heat affected zone (HAZ) on the lower strength material side.

Microstructure evolution mechanism of Al/Mg dissimilar joint during friction stir welding

2020 ◽  
Vol 117 (3) ◽  
pp. 311 ◽  
Author(s):  
Wei Chen ◽  
Wenxian Wang ◽  
Zepeng Liu ◽  
Decheng An ◽  
Ning Shi ◽  
...  
Keyword(s):  
Friction Stir Welding ◽  
Flow Pattern ◽  
Microstructure Evolution ◽  
Ring Structure ◽  
Reflection Effect ◽  
Nugget Zone ◽  
Friction Stir ◽  
Flow Features ◽  
Differential Etching ◽  
Onion Ring

A butt friction stir welding (FSW) process was performed on 6061 Al and AZ31 Mg plates. The microstructure evolutions of the three main regions in the nugget zone (NZ) retained in the FSW joint were systematically investigated to clarify the joint formation mechanism during FSW. The differential etching of these microstructural features was found to produce very vivid flow features. During FSW, the material in the shoulder affected zone (SAZ) was mainly driven by the shoulder, and only a small amount of it was driven by the pin. A strip of Al transferred by the pin from the retreating side (RS) to the advancing side (AS) contacted and reacted with Mg, thus forming intermetallic compounds (IMCs) (e.g., Mg17Al12 and Al3Mg2). Due to the stirring action and tilted angle of the threaded pin, a banded structure (BS) feature tilted at approximately 45° was produced by the alternating lamellae of IMCs. The appearance of an onion ring structure occurred in the severely deformed zone (SDZ), which could be attributed to the reflection effect of the imaginary die wall. Finally, the overall flow pattern of the joint was obtained.

scholarly journals A Comparative Study of Tool-Pin Profile on Process Response of Friction Stir Welding of AA6082-T6 Aluminium Alloy

2017 ◽  
Vol 61 (4) ◽  
pp. 296 ◽  
Author(s):  
Kayode Oyedemi ◽  
Patrick McGrath ◽  
Hannalie Lombard ◽  
Balázs Varbai
Keyword(s):  
Friction Stir Welding ◽  
Material Flow ◽  
Dwell Time ◽  
Research Work ◽  
Welding Process ◽  
Nugget Zone ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Tool Pin ◽  
Welding Direction

This paper presents research work conducted to experimentally establish the process response of two diverse shaped tool-pin profiles for friction stir welding (FSW) AA6082-T6 aluminium. The dwell time was optimised by plunging each tool-pin into a plate sample until the spindle torque stabilised thus ensuring sufficient plasticised material in contact with tool shoulder and the tool-pins. The welds were conducted by employing the optimised dwell time, which in turn revealed a minimised process response time and distance to reach weld stability with respect to (1) the force exerted on the tool-pin in the welding direction, Fx , and (2) the spindle torque, T, during the welding process. Both Fx and T stabilised well within the set (pre-determined) ramp-up distance of 20 mm, indicating that the effective (useful) weld length is maximised. The macrographs also revealed good dynamic material flow within the nugget zone regions and more evident in the nugget zone of the flared tool.

Comparison of Friction Stir and Tungsten Inert Gas Weldments of AA6061-T6

2013 ◽  
Vol 858 ◽  
pp. 19-23
Author(s):  
Mohd Rafiza Shaari ◽  
Zuhailawati Hussain ◽  
Indra Putra Almanar ◽  
Nguyen Van Thuong
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Aluminum Alloys ◽  
Fusion Zone ◽  
Aluminium Alloys ◽  
Inert Gas ◽  
Nugget Zone ◽  
Friction Stir ◽  
Microstructure And Mechanical Properties ◽  
And Tungsten

In this research, 6061-T6 aluminum alloys were welded using friction stir welding and tungsten inert as techniques in order to investigate the microstructure and mechanical properties. FSW of aluminium alloys has showed better mechanical properties compared to the conventional welding, tungsten inert gas (TIG). FSW weldment did not show any pores at the nugget zone compared to fusion zone in TIG weldment which produced a lot of pores.

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

Optimization of friction stir welding parameters of dissimilar aluminium alloys 6061 and 5083 by using response surface methodology

2021 ◽  
pp. 095440622110058
Author(s):  
Sanjeev Verma ◽  
Vinod Kumar
Keyword(s):  
Tensile Strength ◽  
Friction Stir Welding ◽  
Tilt Angle ◽  
Feed Rate ◽  
Aluminium Alloys ◽  
Welded Joint ◽  
Welding Parameters ◽  
Friction Stir ◽  
Industrial Sectors ◽  
Tool Pin

Aluminium and its alloys are lightweight, corrosion-resistant, affordable and high-strength material and find wide applications in shipbuilding, automotive, constructions, aerospace and other industrial sectors. In applications like aerospace, marine and automotive industries, there is a need to join components made of different aluminium alloys, viz. AA6061 and AA5083. In this study friction stir welding (FSW) is used to join dissimilar plates made of AA6061-T6 and AA5083-O. The effect of varying tool pin profile, tool rotation speed, tool feed rate and tilt angle of the tool has been investigated on the tensile strength and percentage elongation of the welded joints. Box-Behkan design, with four input parameters and three levels of each parameter has been employed to decide the set of experimental runs. The regression models have been developed to investigate the influence of welding variables on the tensile strength and elongation of the welded joint. It is revealed that with the increase in welding parameters like tool rpm, tool feed rate and tilt angle of the tool, both the mechanical properties increase, reach a maximum level, followed by a decrease with further increase in the value of parameters. Amongst different types of tool pin profiles used, the FSW tool having straight cylindrical (SC) pin profile is found to yield the maximum strength and elongation of the welded joint for different combinations of welding parameters. Multiple response optimization indicates that the maximum UTS (135.83 MPa) and TE (4.35%) are obtained for the welded joint fabricated using FSW tool having SC pin profile, tilted at 1.11° and operating at tool speed and feed rate of 1568 rpm and 39.53 mm/min., respectively.

scholarly journals Effect of Stirring Pin Rotation Speed on Microstructure and Mechanical Properties of 2A14-T4 Alloy T-Joints Produced by Stationary Shoulder Friction Stir Welding

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1938
Author(s):  
Haifeng Yang ◽  
Hongyun Zhao ◽  
Xinxin Xu ◽  
Li Zhou ◽  
Huihui Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Rotation Speed ◽  
Weld Nugget ◽  
Al Alloy ◽  
Nugget Zone ◽  
T Joints ◽  
Friction Stir ◽  
Stationary Shoulder ◽  
Microstructure And Mechanical Properties

In this study, 2A14-T4 Al-alloy T-joints were prepared via stationary shoulder friction stir welding (SSFSW) technology where the stirring pin’s rotation speed was set as different values. In combination with the numerical simulation results, the macro-forming, microstructure, and mechanical properties of the joints under different welding conditions were analyzed. The results show that the thermal cycle curves in the SSFSW process are featured by a steep climb and slow decreasing variation trends. As the stirring pin’s rotation speed increased, the grooves on the weld surface became more obvious. The base and rib plates exhibit W- or N-shaped hardness distribution patterns. The hardness of the weld nugget zone (WNZ) was high but was lower than that of the base material. The second weld’s annealing effect contributed to the precipitation and coarsening of the precipitated phase in the first weld nugget zone (WNZ1). The hardness of the heat affect zone (HAZ) in the vicinity of the thermo-mechanically affected zone (TMAZ) dropped to the minimum. As the stirring pin's rotation speed increased, the tensile strengths of the base and rib plates first increased and then dropped. The base and rib plates exhibited ductile and brittle/ductile fracture patterns, respectively.

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