Tool geometry optimization in friction stir spot welding of Al-steel joints

2017 ◽  
Vol 26 ◽  
pp. 142-154 ◽  
Author(s):  
Joaquín M. Piccini ◽  
Hernán G. Svoboda
Keyword(s):  
Spot Welding ◽  
Geometry Optimization ◽  
Friction Stir Spot Welding ◽  
Tool Geometry ◽  
Friction Stir ◽  
Steel Joints

Effect of Tool Shape on Temperature Field in Friction Stir Spot Welding

2013 ◽  
Vol 58 (2) ◽  
pp. 595-599 ◽  
Author(s):  
P. Lacki ◽  
Z. Kucharczyk ◽  
R.E. Śliwa ◽  
T. Gałaczyński
Keyword(s):  
Temperature Field ◽  
Solid State ◽  
Spot Welding ◽  
Plastic Material ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Frictional Heat ◽  
Maximum Temperature ◽  
Tool Geometry ◽  
Friction Stir

Friction stir welding (FSW) is one of the youngest methods of metal welding. Metals and its alloys are joined in a solid state at temperature lower than melting points of the joined materials. The method is constantly developed and friction stir spot welding (FSSW) is one of its varieties. In the friction stir spot welding process a specially designed tool is brought into rotation and plunged, straight down, in the joined materials. Heat is generated as a result of friction between the tool and materials, and plastic deformation of the joined materials. Softening (plastic zone) of the joined materials occurs. Simultaneously the materials are stirred. After removal of the tool, cooling down the stirred materials create a solid state joint. Numerical simulation of the process was carried out with the ADINA System based on the finite element method (FEM). The problem was considered as an axisymmetric one. A thermal and plastic material model was assumed for Al 6061-T6. Frictional heat was generated on the contact surfaces between the tool and the joined elements. The model of Coulomb friction, in which the friction coefficient depends on the temperature, was used. An influence of the tool geometry on heat generation in the welded materials was analysed. The calculations were carried out for different radiuses of the tool stem and for different angles of the abutment. Temperature distributions in the welded materials as a function of the process duration assuming a constant value of rotational tool speed and the speed of tool plunge were determined. Additionally, the effect of the stem radius and its height on the maximum temperature was analysed. The influence of tool geometry parameters on the temperature field and the temperature gradient in the welded materials was shown. It is important regarding the final result of FSSW.

Effect of Tool Geometry on Material Flow Behavior of Refill Friction Stir Spot Welding

2016 ◽  
Vol 70 (6) ◽  
pp. 1417-1430 ◽  
Author(s):  
Shude Ji ◽  
Yue Wang ◽  
Zhengwei Li ◽  
Yumei Yue ◽  
Peng Chai
Keyword(s):  
Material Flow ◽  
Spot Welding ◽  
Flow Behavior ◽  
Friction Stir Spot Welding ◽  
Tool Geometry ◽  
Friction Stir

scholarly journals Microstructure and Fatigue Behaviors of Dissimilar A6061/Galvannealed Steel Joints Fabricated by Friction Stir Spot Welding

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3877
Author(s):  
Koki Kumamoto ◽  
Tsuyoshi Kosaka ◽  
Tatsuya Kobayashi ◽  
Ikuo Shohji ◽  
Yuichiro Kamakoshi
Keyword(s):  
Spot Welding ◽  
Friction Stir Spot Welding ◽  
Fatigue Properties ◽  
Joint Interface ◽  
Cycle Fatigue ◽  
Tensile Shear ◽  
Friction Stir ◽  
Shear Fatigue ◽  
Steel Joints ◽  
Residual Melt

The microstructures, tensile shear properties, and tensile shear fatigue properties of dissimilar A6061/Galvannealed steel joints fabricated by friction stir spot welding (FSSW) were investigated. Fe4Al13 phases form as the intermetallic compound (IMC) layer at the joint interface between the A6061 matrix and the galvannealed layer consisting of FeZn7, Fe, and Zn. At the edge of the joint, the stirred layer in which the A6061 matrix and the galvannealed layer are stirred also forms. Moreover, the solidified part of the residual melt discharged from the joint area forms at the outer peripheries of the joint. In this study, FSSW was conducted for two total welding durations: 9 and 10 s. Although the thickness of the remaining A6061 sheet in the welded area decreased with an increase in the welding time, the effects of the total welding time on tensile shear and tensile shear fatigue properties were negligible. A fatigue fracture occurred in the A6061 matrix and at the joint interface at the high cycle fatigue region and the low cycle fatigue region, respectively. In the case of the interfacial fracture, the crack was generated in the solidified part of the residual melt or at the interface between the solidified part and the stirred layer.

Parametric Study of the Mechanical Behavior of FSSW Welded Polymer Plates Using a New Form of Welding Tool

2018 ◽  
Vol 389 ◽  
pp. 205-215
Author(s):  
Lounis Abdallah ◽  
Ould Chikh El Bahri ◽  
Meddah Hadj Miloud ◽  
Gueraiche Larbi ◽  
Hachelaf Kaddour
Keyword(s):  
Spot Welding ◽  
Experimental Tests ◽  
Friction Stir Spot Welding ◽  
Polymer Materials ◽  
Tool Geometry ◽  
Operational Parameters ◽  
Friction Stir ◽  
Lap Shear ◽  
Tool Shape ◽  
Static Resistance

This research paper aims at studying the friction stir spot welding (FSSW) some of thermoplastic polymer materials (HDPE and HDPE-PMMA) using a specifal geometry tool without a pin. The effect of the tool geometry on the welds static resistance was studied via several tool shape, a flat shape below the tool, a shape with concavity angles ranging from 0° to 16° , a flange shape of the sharp-edged tool, a chamfered flange shape and a rounded shape. This work is done to increase the surface area of the weld and further to maximize the static strength of the friction stir spot welding. Experimental tests have been carried out under various operational parameters such as the tool rotation speed, tool plunge depth and dwell time. This later has been carried out to highlight the effect of the tool’s geometry and the operational parameters of the welding on the surface in virtue on static resistance of the friction stir spot welding of thermoplastic polymers. Tests of lap-shear at speed of 5m/s have showed that the tool geometry plays a very important part. This study shows that a FSSW welding tool with 4° concavity angle tool and a rounded flange shape gives the best welding quality for the polymers studied.

Numerical Simulation of Friction Stir Spot Welding of Aluminium-6061 and Magnesium AZ-31B

2022 ◽  
Vol 1048 ◽  
pp. 241-253
Author(s):  
Arindom Baruah ◽  
Jayaprakash Murugesan ◽  
Hemant Borkar
Keyword(s):  
Numerical Simulation ◽  
Spot Welding ◽  
High Efficiency ◽  
Welding Process ◽  
Friction Stir Spot Welding ◽  
Tool Geometry ◽  
Friction Stir ◽  
Finite Element Software ◽  
Point Light ◽  
Joining Process

Friction stir spot welding process is a solid state joining process which has attracted great attention due to its ability to join low melting point light weight alloys such as aluminium and magnesium with high efficiency. In order to understand the complex thermo-mechanical joining process involved with friction stir spot welding, a numerical simulation study was done using ABAQUS finite element software. The simulation primarily aims to interpret the effect of a set of process parameters and tool geometry on the workpiece plates. Johnson-Cook damage criteria model was used to obtain the stress and strain distribution on the workpiece consisting of aluminium 6061 and magnesium AZ-31B placed in a lap configuration. Temperature distribution of the workpiece was obtained by simulating a penalty based frictional contact between the tool and the plate. The thermal results showed that the maximum temperatures attained were significantly lower than the melting points of the base materials indicating that the material mixing and joining occurred as a result of superplastic deformation process instead of melting. Change in material flow behaviour was also observed by the model as pin and shoulder geometries changed.

Study on the new friction stir spot weld joint reinforcement technique on 5754 aluminum alloy

2017 ◽  
Vol 232 (17) ◽  
pp. 2976-2986 ◽  
Author(s):  
Hossein Andalib ◽  
Mohammadreza Farahani ◽  
Moeen Enami
Keyword(s):  
Process Parameters ◽  
Weld Joint ◽  
Spot Welding ◽  
Failure Load ◽  
Friction Stir Spot Welding ◽  
Spot Weld ◽  
Superior Performance ◽  
Tool Geometry ◽  
Spot Welds ◽  
Friction Stir

In this study, new friction stir spot welding method was developed using two different tools in order to create a spot weld without keyhole. The effects of process parameters and tool geometry were considered to improve the weld joint properties. The shear-tensile tests and microstructure study showed that the new method could offer superior performance in comparison to conventional friction stir spot welding. By controlling the process parameters, spot welds with strength about 37% higher than the conventional friction stir spot welds were obtained. The stir zone grain size of the prepared samples in the optimum welding conditions was decreased about four times than the base metal. It was observed that the tool plunge depth in both welding and refilling steps play a key role in creating a sound high strength welded joint. The failure load of the spot welds manufactured by concave shoulder was found to be about 7% higher than the failure load of the prepared spot welds by the flat shoulder.

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