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 Effect of Shoulder–Workpiece Interference Depth on the Quality of Friction Stir Welding of AA7075-T6 Aluminium Alloy

2019 ◽  
Vol 26 (1) ◽  
pp. 150-159
Author(s):  
Abbas Akram Abbas ◽  
Hazim H. Abdulkadhum
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Welding Process ◽  
High Strength ◽  
Filling Defect ◽  
Welding Quality ◽  
Left Hand ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Welding Surface

The joining of high strength aluminium alloy AA7075-T6 sheets of 3 mm thickness was an attempt utilizing friction stir welding process. The effect of interference depth between tool shoulder and surface workpiece on the welding quality and its effect on the mechanical and metallography properties of welded joints were studied. This process is carried out using a composite tool consists of a concave shoulder made of H13 tool steel and cylindrical left-hand thread with 1mm pitch pin (probe) made of cobalt-based alloy MP159. The dimensions of tools were 14mm shoulder diameter and the pin has 5mm diameter and 2.7mm length. The tool rotation speed and welding speed were 981 rpm 169 mm/min respectively, and the tilt angle was 2°. The range of interference depth between the shoulder and workpiece was selected (0.05, 0.1, 0.15, 0.2, 0.25, and 0.3) mm. various tests were executed to evaluate the welding quality. The results show that lack of filling defect appeared on the welding surface at the interference depth 0.05 mm. An invisible tunnel and lack of penetration in the bottom of the stir zone appeared when the interference depths were 0.1 mm and 0.15 mm. Defect-free welds obtained when interference depths were (0.2, 0.25, and 0.3) mm. The welding efficiency of the defect-free welds was in the range (85.3-92.3%) depending on the ultimate tensile strength of the parent alloy.

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.

Parametric optimization of friction stir welding process for marine grade aluminum alloy

2019 ◽  
Vol 10 (2) ◽  
pp. 162-175 ◽  
Author(s):  
Amit Goyal ◽  
Ramesh Kumar Garg
Keyword(s):  
Friction Stir Welding ◽  
Yield Strength ◽  
Welding Process ◽  
Tool Material ◽  
Weld Nugget ◽  
Quadratic Model ◽  
Content Type ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Fsw Parameters

Purpose The purpose of this paper is to deal with the experimental data related to the friction stir welding (FSW) of marine grade Al-Mg4.2 alloy. Mathematical models are developed to study the individual and interaction effects of input variables on the performance characteristics of joints. FSW parameters are optimized to maximize the yield strength and weld nugget microhardness of the welded joints. Design/methodology/approach Response surface methodology is applied to establish the mathematical relationship between six input factors, namely, tool rotational speed, transverse speed, tool shoulder diameter, tool material hardness, tilt angle and pin profile; and two response variables, namely, yield strength and weld nugget microhardness. Six factors–five-level rotatable central composite matrix is used for the design of experiments. The quadratic model is used, as suggested by the design expert software, to express the response parameters as a function of investigated input parameters. The competence of the developed models is verified through analysis of variance. Findings The present investigation clearly indicates that the studied input factors have a significant effect on the quality of the joints. The optimal combination of input factors is determined to achieve the desired responses. Originality/value This paper teems a new look on tensile and hardness properties of Al-Mg4.2 joints by relating the microstructure, fractrographs and grains distribution with the dynamic recrystallization and plasticized material movement during the FSW process. The outcome of this research will help in seizing the opportunities of joining Al-Mg4.2 alloy using FSW, in the offshore and marine applications.

scholarly journals Comprehensive Analysis of the Microstructure and Mechanical Properties of Friction-Stir-Welded Low-Carbon High-Strength Steels with Tensile Strengths Ranging from 590 MPa to 1.5 GPa

2021 ◽  
Vol 11 (12) ◽  
pp. 5728
Author(s):  
HyeonJeong You ◽  
Minjung Kang ◽  
Sung Yi ◽  
Soongkeun Hyun ◽  
Cheolhee Kim
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Joint Strength ◽  
Solid Phase ◽  
Welding Process ◽  
High Strength Steels ◽  
High Strength ◽  
Low Carbon ◽  
Friction Stir ◽  
Welding Processes

High-strength steels are being increasingly employed in the automotive industry, requiring efficient welding processes. This study analyzed the materials and mechanical properties of high-strength automotive steels with strengths ranging from 590 MPa to 1500 MPa, subjected to friction stir welding (FSW), which is a solid-phase welding process. The high-strength steels were hardened by a high fraction of martensite, and the welds were composed of a recrystallized zone (RZ), a partially recrystallized zone (PRZ), a tempered zone (TZ), and an unaffected base metal (BM). The RZ exhibited a higher hardness than the BM and was fully martensitic when the BM strength was 980 MPa or higher. When the BM strength was 780 MPa or higher, the PRZ and TZ softened owing to tempered martensitic formation and were the fracture locations in the tensile test, whereas BM fracture occurred in the tensile test of the 590 MPa steel weld. The joint strength, determined by the hardness and width of the softened zone, increased and then saturated with an increase in the BM strength. From the results, we can conclude that the thermal history and size of the PRZ and TZ should be controlled to enhance the joint strength of automotive steels.

A Thermo-Fluid Analysis of the Friction Stir Welding Process

2007 ◽  
Vol 539-543 ◽  
pp. 3832-3837 ◽  
Author(s):  
D. Jacquin ◽  
Christophe Desrayaud ◽  
Frank Montheillet
Keyword(s):  
Friction Stir Welding ◽  
Bulk Material ◽  
Welding Process ◽  
Vertical Motion ◽  
Velocity Fields ◽  
Fluid Simulation ◽  
Metal Sheet ◽  
Friction Stir ◽  
Tool Shoulder ◽  
Fluid Analysis

The thermo-mechanical simulation of Friction Stir Welding focuses the interest of the welding scientific and technical community. However, literature reporting material flow modeling is rather poor. The present work is based on the model developed by Heurtier [2004] and aims at improving this thermo-fluid simulation developed by means of fluid mechanics numerical and analytical velocity fields combined together. These various velocity fields are investigated separately and especially according to the power dissipated during the flow. Boundary conditions are considered through a new approach based on the kinematic analysis of the thread of the pin. An equilibrium is established between the vertical motion of the bulk material dragged in the depth of the metal sheet, and its partial circulation around the pin. The analyses of the obtained velocity fields enable the understanding of the welded zone asymmetry and highlights the bulk material mixing between the welded coupons in the depth of the sheet. A regression is performed on the relative sliding velocity of the aluminium according to the surface of the tool: shoulder and pin. Two dimension flow lines in the depth of the metal sheet are then obtained and successfully compared with the results obtained by Colegrove (2004) [1].

scholarly journals Analysis of the influence of position of welding materials on the FSW seams properties for three dissimilar aluminium alloy

2018 ◽  
Vol 178 ◽  
pp. 03003 ◽  
Author(s):  
Ana Bosneag ◽  
Marius Adrian Constantin ◽  
Eduard Niţu ◽  
Monica Iordache
Keyword(s):  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
Process Parameters ◽  
Arc Welding ◽  
Welding Process ◽  
Dissimilar Materials ◽  
Workpiece Material ◽  
Friction Stir ◽  
Welding Joints ◽  
Welding Materials

Friction Stir Welding, abbreviated FSW is a new and innovative welding process. This welding process is increasingly required, more than traditional arc welding, in industrial environment such us: aeronautics, shipbuilding, aerospace, automotive, railways, general fabrication, nuclear, military, robotics and computers. FSW, more than traditional arc welding, have a lot of advantages, such us the following: it uses a non-consumable tool, realise the welding process without melting the workpiece material, can be realised in all positions (no weld pool), results of good mechanical properties, can use dissimilar materials and have a low environmental impact. This paper presents the results of experimental investigation of friction stir welding joints to three dissimilar aluminium alloy AA2024, AA6061 and AA7075. For experimenting the value of the input process parameters, the rotation speed and advancing speed were kept the same and the position of plates was variable. The exit date recorded in the time of process and after this, will be compared between them and the influence of position of plate will be identified on the welding seams properties and the best position of plates for this process parameters and materials.

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 The Effect of Copper and Brass on Friction Stir Welded Dissimilar Aluminium Alloy When Used as in Thin Sheet Form

2016 ◽  
Vol 45 (2) ◽  
pp. 118-122
Author(s):  
G. Gopala Krishna ◽  
P.Ram Reddy ◽  
M.Manzoor Hussain
Keyword(s):  
Aluminium Alloy ◽  
Aluminium Alloys ◽  
Low Cost ◽  
Thin Sheet ◽  
Welding Process ◽  
Cost Effective ◽  
Tensile Tests ◽  
Fusion Welding ◽  
Friction Stir ◽  
Effect Of Copper

In recent year’s aluminium and aluminium alloys are most widely used in many applications because of light weight, good formability and malleability, corrosion resistance, moderate strength and low cost. Friction Stir Welding (FSW) process is efficient and cost effective method for welding aluminium and aluminium alloys. FSW is a solid state welding process that means the material is not melted during the process. Complete welding process accomplishes below the melting point of materials so it overcomes many welding defects that usually happens with conventional fusion welding technique which were initially used for low melting materials. Though this process is initially developed for low melting materials but now process is widely used for a variety of other materials including titanium, steel and also for composites. The present butt jointed FSW experimental work has been done in two ways. Initially a comparison of tensile properties of friction stir (FS) welded similar aluminium alloy (AA6351 with AA6351) and dissimilar aluminium alloy (AA6351 with AA5083) combinations. Later the effect of impurities (copper and brass) in sheet form (0.1 mm thick) when used as insert in between two dissimilar aluminium alloy (AA6351 with AA5083) plates during FSW. Tensile tests were performed for these combinations and results were compared for with and without using strip material (copper and brass).

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