Effect of double-sided friction stir welding on the mechanical and microstructural characteristics of AA5754 aluminium alloy

2021 ◽  
Vol 63 (9) ◽  
pp. 829-835
Author(s):  
Sare Çelik ◽  
Fatmagül Tolun

Abstract AA5754Al alloy is widely used in industry. However, as in the case of all Al alloys, the 5xxx series Al alloys cannot be easily joined through fusion welding techniques. To address this problem, in this study, the effect of double-sided friction stir welding at various tool rotational speeds (450, 710, and 900 rpm), feeding rates (40, 50, and 80 mm × min-1), and tool tilt angles (0°, 1°, 2°) on the welding parameters and mechanical and microstructural characteristics of AA5754 Al alloy was determined. Tensile strength tests and microhardness tests were performed to examine the mechanical properties of the welded specimens. The microstructures of the welded zone were examined by obtaining optical microscopy and scanning electron microscopy images. The tensile test results indicated that the specimens exhibited the highest welding performance of 95.17 % at a tool rotational speed, feed rate, and tool tilt angle of 450 rpm, 50 mm × min-1 and 1°, respectively.

2013 ◽  
Vol 376 ◽  
pp. 42-48 ◽  
Author(s):  
S.N. Pandya ◽  
J.V. Menghani

Many engineering applications in aerospace and automotive field require joining of dissimilar 5xxx to 6xxx Al alloys. Dissimilar Al alloy joints are used for industrial applications due to technical & economic reasons. However, due to different metallurgical behaviour & mechanical properties, joining of dissimilar Al alloys presents a number of challenges. Due to high temperature generation most of the fusion welding techniques are not suitable. In addition, other pressure welding techniques such as – Ultrasonic welding, Roll bonding, Diffusion bonding and Friction welding have some limitation. Hence, friction stir welding (FSW) can be considered to be the most suitable method to join dissimilar Al alloys due to solid-state nature of the process. Since invention, friction stir welding has been a matter of research and investigation for years. In its history of two decades, Friction Stir welding was investigated for joining dissimilar Al alloys during the last decade. Most of studies demonstrated that good quality joints between dissimilar Al alloys can be produced by the Friction Stir Welding (FSW) process. The present study is a chronological & critical review of recent studies on joining of dissimilar 5xxx to 6xxx Al alloys by friction stir welding.


2021 ◽  
pp. 186-186
Author(s):  
Darko Veljic ◽  
Marko Rakin ◽  
Aleksandar Sedmak ◽  
Nenad Radovic ◽  
Bojan Medjo ◽  
...  

The influence of friction stir welding (FSW) parameters on thermo-mechanical behaviour of the material during welding is analysed. An aluminium alloy is considered (Al 2024 T351), and different rotating speed and welding speed are applied. Finite element model consists of the plate (Al alloy), backing plate and welding tool, and it is formed and solved in software package Simulia Abaqus. The influence of the welding conditions on material behaviour is taken into account by application of the Johnson-Cook material model. The rotation of the tool affects the results: if increased, it contributes to an increase of friction-generated heat intensity. The other component of the generated heat, the plastic deformation of the material, is negligibly changed. When the welding speed is increased, the intensity of friction-generated heat decreases, while the heat generation due to plastic deforming increases. Combined, these two effects cause small change of the total heat generation. For the same welded joint length, the plate welded by lower speed will be heated more intensively. The changes of the heat generation influence both the temperature field and reaction force, which are also considered.


Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1607
Author(s):  
Amir Hossein Baghdadi ◽  
Zainuddin Sajuri ◽  
Mohd Zaidi Omar ◽  
Armin Rajabi

Friction stir welding (FSW) is an alternative method to join aluminum (Al) alloys in a solid-state condition. However, the coarsening or dissolution of precipitation hardening phases in the welding zone causes strength reduction or softening behavior in the welded area of age-hardened Al alloys. Therefore, this research aimed to improve the mechanical properties of an FSW Al–Mg–Si alloy via post-weld heat treatment (PWHT) and the possibility of controlling the abnormal grain growth (AGG) using different welding parameters. FSW was performed with different rotational and travel speeds, and T6 heat treatment was carried out on the FSW samples as the PWHT. The results showed a decrease in the strength of the FSW samples compared with that of the base material (BM) due to the dissolution of precipitation hardening particles in the heat-affected zone. However, the emergence of AGG in the microstructure after the T6-PWHT was identified as the potential event in the microstructure of the PWHT samples. It is found that the AGG of the microstructure in similar joints of Al6061(T6) was governed by the welding parameters. The results proved that PWHT was able to increase the tensile properties of the welded samples to values comparable to that of Al6061(T6)-BM. The increased mechanical properties of the FSW joints were attributed to a proper PWHT that resulted in a homogeneous distribution of the precipitation hardening phases in the welding zones.


2016 ◽  
Vol 857 ◽  
pp. 228-231
Author(s):  
Ho Sung Lee ◽  
Ye Rim Lee ◽  
Kyung Ju Min

Aluminum-Lithium alloys have been found to exhibit superior mechanical properties as compared to the conventional aerospace aluminum alloys in terms of high strength, high modulus, low density, good corrosion resistance and fracture toughness at cryogenic temperatures. Even though they do not form low-melting eutectics during fusion welding, there are still problems like porosity, solidification cracking, and loss of lithium. This is why solid state friction stir welding is important in this alloy. It is known that using Al-Cu-Li alloy and friction stir welding to super lightweight external tank for space shuttle, significant weight reduction has been achieved. The objective of this paper is to investigate the effect of friction stir tool rotation speed on mechanical and microstructural properties of Al-Cu-Li alloy. The plates were joined with friction stir welding process using different tool rotation speeds (300-800 rpm) and welding speeds (120-420 mm/min), which are the two prime welding parameters in this process.


2014 ◽  
Vol 875-877 ◽  
pp. 1477-1482
Author(s):  
Tomáš Kupec ◽  
Ivana Hlaváčová ◽  
Milan Turňa

The work deals with welding of aluminium alloy typeAlMg4,5Mn and magnesium alloy type AZ 31 in solid state by FSW (Friction Stir Welding) process. Experiments were performed in cooperation with VÚZ PI SR (Welding Research Institute Industrial Institute of Slovak Republic) Bratislava, which has available a new installed equipment type FSW LM 060 manufactured in China. Welding parameters and conditions were proposed and approved. Quality of fabricated joints was assessed by optical microscopy, micro hardness measurement and radiographic test - RT. It was supposed that optimisation of welding parameters would allow to fabricate the joints of acceptable quality that might compete to technologies of fusion welding, including welding with concentrated power sources.


Author(s):  
Ashish Bist ◽  
JS Saini ◽  
Vikas Sharma

Aluminum matrix composites have received considerable attention due to their high specific strength and specific stiffness, high hardness, and wear resistance along with being light in weight. These composites are preferably joined using friction stir welding process. The major concern in friction stir welding is the wear of the welding tool pin which is the backbone of the process. The wear is due to the prolonged contact between the tool and the harder reinforcements in the composite materials. The present work deals with the study of tool wear and its surface roughness with respect to different selected friction stir welding parameters such as rotational speed, transverse speed, length of weld, and different composition of Aluminum composite. It was found that the total amount of material removed from the tool and the surface roughness of the tool is in direct proportion to the rotational speed of the tool and the length of the weld but inversely proportional to the transverse rate. The increase in wt.% of SiC reinforcement leads to the higher tool wear but reduces the surface roughness of the tool.


Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 390
Author(s):  
Cyril Vimalraj ◽  
Paul Kah

To reduce environmental impacts and ensure competitiveness, the fabrication and construction sectors focus on minimizing energy and material usage, which leads to design requirements for complex structures by joining of similar and dissimilar materials. Meeting these industrial demands requires compatible materials with improved properties such as good weight-to-strength ratios, where aluminum (Al) and its alloys are competing candidates for various complex applications. However, joining Al with fusion welding processes leads to joint deterioration. Friction stir welding (FSW) produces joints at temperatures below the melting temperature, thus avoiding flaws associated with high heat input, yet requires improvement in the resultant joint properties. Recent studies have shown that nanoparticle reinforcement in FSW joints can improve weld properties. The main focus of this study is to critically review similar and dissimilar friction stir welding of AA5083 and AA6082 with carbide and oxide nanoparticle reinforcement. The study also discusses the effect of welding parameters on reinforcement particles and the effect of nanoparticle reinforcement on weld microstructure and properties, as well as development trends using nanoparticles in FSW. Analysis shows that friction stir welding parameters have a significant influence on the dispersion of the reinforcement nanoparticles, which contributes to determining the joint properties. Moreover, the distributed nanoparticles aid in grain refinement and improve joint properties. The type, amount and size of reinforcement nanoparticles together with the welding parameters significantly influence the joint properties and microstructures in similar and dissimilar Al welds. However, research is still required to determine the strengthening mechanism used by nanoparticles and to assess other nanoparticle additions in FSW of Al alloys.


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