Refill friction stir spot welding of 7075-T6 aluminium alloy single-lap joints with polymer sealant interlayer

2018 ◽  
Vol 201 ◽  
pp. 389-397 ◽  
Author(s):  
Andrzej Kubit ◽  
Dawid Wydrzynski ◽  
Tomasz Trzepiecinski
Keyword(s):  
Aluminium Alloy ◽  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Friction Stir ◽  
Single Lap Joints ◽  
Polymer Sealant

Characterization and Optimization of Flat Friction Stir Spot Welding of Triple Sheet Dissimilar Aluminium Alloy Joints

Silicon ◽  
2021 ◽  
Author(s):  
Sachin Jambhale ◽  
Sudhir Kumar ◽  
Sanjeev Kumar
Keyword(s):  
Aluminium Alloy ◽  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Friction Stir

scholarly journals Fatigue Life Assessment of Refill Friction Stir Spot Welded Alclad 7075-T6 Aluminium Alloy Joints

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 633
Author(s):  
Andrzej Kubit ◽  
Mateusz Drabczyk ◽  
Tomasz Trzepiecinski ◽  
Wojciech Bochnowski ◽  
Ľuboš Kaščák ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Aluminium Alloy ◽  
Crack Growth ◽  
Fatigue Failure ◽  
Spot Welding ◽  
Lap Joints ◽  
Life Assessment ◽  
Loading Conditions ◽  
Friction Stir ◽  
Lap Shear

Refill Friction Stir Spot Welding (RFSSW) shows great potential to be a replacement for single-lap joining techniques such as riveting or resistance spot welding used in the aircraft industry. In this paper, the fatigue behaviour of RFSSW single-lap joints is analysed experimentally in lap-shear specimens of Alclad 7075-T6 aluminium alloy with different thicknesses, i.e., 0.8 mm and 1.6 mm. The joints were tested under low-cycle and high-cycle fatigue tests. Detailed observations of the fatigue fracture characteristics were conducted using a scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDS). The locations of fatigue failure across the weld, fatigue crack initiation, and propagation behaviour are discussed on the basis of the SEM analysis. The possibility of predicting the propagation of fatigue cracks in RFSSW joints is verified based on Paris’s law. Two fatigue failure modes are observed at different load levels, including shear fracture mode transverse crack growth at high stress-loading conditions and at low load levels, and destruction of the lower sheet due to stretching as a result of low stress-loading conditions. The analysis of SEM micrographs revealed that the presence of aluminium oxides aggravates the inhomogeneity of the material in the weld nugget around its periphery and is a source of crack nucleation. The results of the fatigue crack growth rate predicted by Paris’s law were in good agreement with the experimental results.

Simulative Model for the Evaluation of Thermo-Mechanical Effects in Friction Stir Spot Welding (FSSW) of Aluminum Sheets

2014 ◽  
Vol 622-623 ◽  
pp. 557-566
Author(s):  
G. D’Urso ◽  
Claudio Giardini
Keyword(s):  
Process Parameters ◽  
Spot Welding ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Local Pressure ◽  
Friction Stir ◽  
Welding Forces ◽  
Set Up ◽  
Simulative Model

A study was performed to evaluate how the Friction Stir Spot Welding process parameters affect both the thermal distribution in the welding region and the welding forces. An experimental campaign was performed by means of a CNC machine tool and FSSW lap joints on AA6060-T6 aluminum alloy plates having a thickness of 2+2 mm were executed. Five thermocouples were inserted into the samples at a specific distance from the specimen center. A set of tests was carried out by varying the process parameters, namely rotational speed, axial feed rate, plunging depth and dwell time. Axial welding forces were also measured during the execution of the experiments by means of a piezoelectric load cell. The experimental data collected were used to set up and to validate a simulative model of the process. In particular, a 2D FEM model was set up using the commercial code Deform 2D. A 2-dimensional FEM code was preferred in order to guarantee a very simple and practical model able to achieve results in a very short time. Since it is not possible to simulate the rotation of the tool in a 2D configuration, a specific external routine for the calculation of the developed thermal energy due to the friction between tool and workpiece was set up and implemented into the code starting from the local pressure distribution along the contact area.

Generating Lap Joints Via Friction Stir Spot Welding on DP780 Steel

10.3791/58633 ◽  
2019 ◽  
Author(s):  
Tai-I Hsu ◽  
Meng-Hsiu Tsai
Keyword(s):  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Friction Stir ◽  
Dp780 Steel

Towards Tool Path Numerical Simulation in Modified Friction Stir Spot Welding Processes

2009 ◽  
Vol 83-86 ◽  
pp. 1220-1227
Author(s):  
Gianluca Buffa ◽  
Livan Fratini
Keyword(s):  
Spot Welding ◽  
Tool Path ◽  
Base Material ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Lap Joints ◽  
Hollomon Parameter ◽  
Friction Stir ◽  
Strain And Strain Rate ◽  
Welding Processes

Spot welding can be considered a very common joining technique in automotive and transportation industries as it permits to obtain effective lap-joints with short process times and what is more it is easily developed through robots and automated systems. Recently the Friction Stir Spot Welding (FSSW) process has been proposed as a natural evolution of the already known Friction Stir Welding (FSW) process, allowing to obtain sound spot joints that do not suffer from the insurgence of typical welding defects due to the fusion of the base material. In the paper, a modified Friction Stir Spot Welding (FSSW) process, with a spiral circular movement given to the tool after the sinking stage, is proposed. A continuum based numerical model for Friction Stir Spot Welding process is developed, that is 2D Lagrangian implicit, coupled, rigid-viscoplastic. This model is used to investigate the distribution of the main field variables, namely temperature, strain and strain rate, as well as the Zener-Hollomon parameter which, in turn, strongly affects the Continuous Dynamic Recrystallization (CDRX) process that takes place in the weld nugget. Numerical and experimental results are presented showing the effects of the process parameters on the joint performances and the mechanical effectiveness of the modified process.

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