scholarly journals Mechanical and structural evaluation of friction stir welded 6061 aluminium alloy lap joints at different welding speeds

2016 ◽  
Vol 54 (05) ◽  
pp. 351-361 ◽  
Author(s):  
F. GHARAVI ◽  
F. FADAEIFARD ◽  
K. A. MATORI ◽  
R. YUNUS ◽  
N. K. OTHMAN
Keyword(s):  
Aluminium Alloy ◽  
Lap Joints ◽  
Friction Stir ◽  
Structural Evaluation ◽  
6061 Aluminium Alloy

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.

The influence of the shoulder depth on the properties of the thin sheet joint made by FSW technology

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Rafał Burek ◽  
Dawid Wydrzyński ◽  
Andrzej Kubit ◽  
Waldemar Łogin
Keyword(s):  
Aluminium Alloy ◽  
Joint Strength ◽  
Welding Process ◽  
Lap Joints ◽  
Numerical Control ◽  
Thick Sheet ◽  
Content Type ◽  
Friction Stir ◽  
Tool Shoulder ◽  
The Face

Purpose This paper aims to experimentally determine the influence of the tool shoulder depth value on the structural and strength properties of the single lap joints made of 7075-T6 aluminium alloy made with friction stir welding (FSW) technology. The aim of the preliminary tests is to optimize the parameters of joining process of thin-walled structures such as the skin-stringer joint or skin-frame joint of the aircraft fuselage. The tests were carried out for materials commonly used in such structures, i.e. 1.6 mm thick sheet 7075–T6 aluminium alloy with cladding on both sides (cladding thickness 4% per each side). The layer of clad protects plates from corrosion. Design/methodology/approach This study shows the results of the investigation for the joining of 7075–T6 ALCLAD aluminium alloy sheets. The welding process was carried out on a computer numerical control milling machine SOLARUCE TA–20A. Linear FSW welding was performed using a commercial tool from RSS SCHILLING with the symbol 10–K–4–Z–M–O, which is fabricated of hot work tool steel. Constant parameters of the technological process were applied. The welding process was executed for different values of the shoulder depth ZS. Findings This paper investigated the dependence between the thinning of the welded material and the depth value of the tool shoulder during the FSW process. The influence of the depth value of tool shoulder on joint strength in the static tensile/shear test was also performed. With the increase of the depth of the tool, the size of flash and structures of the face of the joint changes as well (its annular surface resulting from the tool’s work and the accompanying process of material flow on the run-off side). Such conditions in the process require a proper tool depression to reduce the occurrence of flash and minimize material thinning to achieve high joint strength and maintain the conditions for plasticizing the material. Practical implications Based on the experimental tests carried out, a number of guidelines for the correct conduct of the welding process can be outlined. Originality/value Taking into account the various aspects of the process, the optimal range of the tool depth into the material is a value of approximately 0.06 mm. At this value, the face of the weld is not porous; the flash is easily removed; and the strength of the joint and the deformation of contact line are at an acceptable quality level.

scholarly journals Shear and Hardness Properties Study of AA-6061 Aluminium Alloy Lap-Joints Produced by Friction Stir Spot Welding Process Using H13 Tool Steel

2021 ◽  
Vol 6 (3) ◽  
pp. 187-194
Author(s):  
Afif Mohamad Hanapiah ◽  
Sumaiya Islam ◽  
Neamul Khandoker ◽  
Mazid Abdul Md
Keyword(s):  
Aluminium Alloy ◽  
Weight Ratio ◽  
Welding Process ◽  
High Heat ◽  
Lap Joints ◽  
Al Alloy ◽  
Cnc Milling ◽  
Excessive Heat ◽  
Friction Stir ◽  
Welding Processes

By virtue of high-strength verses weight ratio aluminium alloys are achieving attentions in automobile, marine, and aircraft industries as it reduces the fuel consumption for running the vehicles. But their main drawback is the destruction of their carefully engineered microstructures by high heat generated in traditional welding processes. Friction Stir Welding (FSW) minimizes excessive heat in the welding zone and does not   influence the microstructural features.  FSW is currently one of the recommended solutions for manufacturing aluminium alloy welded machine parts. In this study, AA6061 Al-alloy strips were lap joined using the improvised FSW setup tool clamping it on the spindle of a CNC milling machine with the speed rate varied from 1000 rpm to 3000 rpm, and three different feed rates 5, 15, and 25 mm/min. Shear strength experiments of these joints revealed that samples created with the speed rate of 1000 rpm and feed rate of 25 mm/min performed best showing the highest load carrying capacity of 8976 N with elongation of 1.04%. They also demonstrated highest Vickers hardness value of 31 at the centre of the weldment.

Failure mechanisms of refill friction stir spot welded 7075-T6 aluminium alloy single-lap joints

2017 ◽  
Vol 94 (9-12) ◽  
pp. 4479-4491 ◽  
Author(s):  
Andrzej Kubit ◽  
Magdalena Bucior ◽  
Dawid Wydrzyński ◽  
Tomasz Trzepieciński ◽  
Maciej Pytel
Keyword(s):  
Aluminium Alloy ◽  
Failure Mechanisms ◽  
Lap Joints ◽  
Friction Stir ◽  
Single Lap Joints ◽  
Spot Welded
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