scholarly journals Bobbin Tool Friction Stir Welding of Aluminum Using Different Tool Pin Geometries: Mathematical Models for the Heat Generation

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 438
Author(s):  
Mohamed M. Z. Ahmed ◽  
Mohamed I. A. Habba ◽  
Nabil Jouini ◽  
Bandar Alzahrani ◽  
Mohamed M. El-Sayed Seleman ◽  
...  

In this work, three mathematical models for the heat generation during bobbin tool friction stir welding (BT-FSW) of aluminum using three tool pin geometries have been proposed. The models have utilized and updated the available models for the heat generation during the conventional tool friction stir welding (CT-FSW). For the validation of the models, BT-FSW experiments have been carried out for aluminum alloy AA1050 using three different pin geometries (cylindrical, square, and triangular), at different welding speeds of 200, 400, 600, 800, and 1000 mm/min and a constant tool rotation speed of 600 rpm. The welding temperatures during BT-FSW have been measured to be compared with that calculated from the models at the same parameters. It has been found that the calculated welding temperatures from the models and that measured during BT-FSW are in good agreement at all the investigated welding speeds especially in case of the square and cylindrical pins, proving the validity of the developed models for the predication of the heat generation as well as the welding temperatures. This will allow proper designing of the BT-FSW parameters and avoiding the conditions that can deteriorate the joint quality and properties.

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.


2016 ◽  
Vol 20 (1) ◽  
pp. 247-254
Author(s):  
Darko Veljic ◽  
Bojan Medjo ◽  
Marko Rakin ◽  
Zoran Radosavljevic ◽  
Nikola Bajic

Temperature, plastic strain and heat generation during the plunge stage of the friction stir welding (FSW) of high-strength aluminium alloys 2024 T3 and 2024 T351 are considered in this work. The plunging of the tool into the material is done at different rotating speeds. A three-dimensional finite element (FE) model for thermomechanical simulation is developed. It is based on arbitrary Lagrangian-Eulerian formulation, and Johnson-Cook material law is used for modelling of material behaviour. From comparison of the numerical results for alloys 2024 T3 and 2024 T351, it can be seen that the former has more intensive heat generation from the plastic deformation, due to its higher strength. Friction heat generation is only slightly different for the two alloys. Therefore, temperatures in the working plate are higher in the alloy 2024 T3 for the same parameters of the plunge stage. Equivalent plastic strain is higher for 2024 T351 alloy, and the highest values are determined under the tool shoulder and around the tool pin. For the alloy 2024 T3, equivalent plastic strain is the highest in the influence zone of the tool pin.


2014 ◽  
Vol 783-786 ◽  
pp. 1794-1807
Author(s):  
Qing Yu Shi ◽  
Gao Qiang Chen ◽  
Xi Bo Wang ◽  
Xu Kang

Friction stir welding (FSW) is an advanced solid state joining technology, which was invented by TWI in 1991. During the process, large amount of heat is generated due to the friction between the tool and the material. As a result, the metal around the tool is softened as the temperature rises, and significant plastic flow occurs. So FSW is a complex process with multi-field coupled phenomena. Material flow plays a central role in FSW. But it is still difficult to reveal the material flow regime and joining mechanism during FSW process. Numerical simulation is a powerful tool for investigating the metal-flow-related complex phenomena during FSW. Meanwhile, numerical simulation could also help to optimize FSW tool design and FSW parameters. In this paper, we review the recent development in simulation of material flow during FSW. Then, the important issues in modeling multi field coupled phenomena during FSW are summarized, which include the heat generation mechanism, the temperature and strain rate dependent material’s behavior, and the interaction between tool and material. Finally, a comprehensive simulation model is presented, which enables advanced study on the coupled phenomena of heat generation, temperature distribution, material flow, and defects formation. This model has shown potential applications in simulating the relation between the transport of material and the macrostructure formation or defects formation. In spite of these progresses, simulation of material flow during FSW still need quite a lot of researches to fulfill industry requirement.


Author(s):  
A. J Amroliya ◽  
Dr. D. B Jani ◽  
Dr. R. K Shukla

Friction stir welding is a solid state joining process which is used to join metals and alloys having low weldability .Study about the effect of FSW parameters like tool rpm, tool transverse speed and tool pin profile. A vertical milling head is used to produce FSW joints. In this study, solid state joining technology of friction stir welding (FSW) was carried out for Al and Mg butt joints and other dissimilar metals. This review article thoroughly highlights the influence of FSW working parameters on microstructure, mechanical properties. This effort not only sets eminent outcomes of the preceding research personnel but also proposes forthcoming guidelines for FSW of dissimilar metals.


2017 ◽  
Vol 24 (3) ◽  
pp. 439-446
Author(s):  
Zhang Peilei ◽  
Yan Hua ◽  
Li Chonggui ◽  
Yu Zhishui ◽  
Lu Qinghua

AbstractA three-dimensional heat transfer model for friction stir welding is presented in this paper. A moving coordinate was introduced to reduce the difficulty of modeling the moving tool. Heat input from the tool shoulder and the tool pin were considered in the model. The plastic deformation heat was introduced into the model, too. It is clear that the heat production increased owing to plastic deformation, and this process depends on the stress level. Temperature measurement experiments were done to validate the calculated results. The calculated results were in good agreement with the experimental results. Preheating the workpiece is beneficial to obtain a good weld seam.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7565
Author(s):  
Supat Chupradit ◽  
Dmitry Olegovich Bokov ◽  
Wanich Suksatan ◽  
Michał Landowski ◽  
Dariusz Fydrych ◽  
...  

The friction stir welding (FSW) of tool pin geometry plays a critical role in the final properties of the produced joint. The tool pin geometry directly affects the generation of heat and the flow of internal materials during the FSW process. The effects of the FSW tool pin angle on heat generation and internal flow have not been quantitatively investigated in detail. In this manuscript, a validated Computational Fluid Dynamic (CFD) model was implemented to analyze the effects of pin angle on the thermo-mechanical action during the FSW process of AA5058 Al-Mg alloy. Experimental test results validate the thermal outcomes of the used model. The obtained results revealed that, when the pin angle is increased, the heat generation decreases while the mechanical action of the tool increases. The internal heat distribution at a higher pin angle is symmetrical. The higher mechanical action of the tool decreases the viscosity of the internal materials and increases stirring action (materials flow) around the pin. Furthermore, plastic flow near the tool increased stirring action and formed a larger stir zone in the joint area.


2015 ◽  
Vol 799-800 ◽  
pp. 434-438 ◽  
Author(s):  
H.A.D. Hamid ◽  
A.A. Roslee

This paper presents an investigation of research objectives on the effect of tilt angle on microstructure and mechanical properties of dissimilar aluminum alloy sheets between AA5083 and AA6061, 5mm plates by using Friction Stir Welding (FSW) process in butt joint. The base materials of AA5083 and AA6061 were located on the retreating side (RS) and advancing side (AS), respectively. The welding process and the welding parameters such as tool pin profile, tool rotation speed, welding speed and tilt angle influenced the mechanical properties of the Friction Stir Welding joints significantly. For this experiment, the Friction Stir Welding materials joined under five different tilt angles (from 0oto 4o) with 86mm/min of welding speed and 910 rpm of tool rotation speed which were set similarly. Microscopic examination on the weld samples showed significant variation in the microstructure especially in the region of heat-affected zone (HAZ), weld nugget or dynamically recrystallized zone (DXZ) and in the base metal.


2014 ◽  
Vol 903 ◽  
pp. 200-205
Author(s):  
Irfan Hilmy ◽  
Erry Yulian Triblas Adesta ◽  
Muhammad Riza

Friction Stir Welding (FSW) is getting its popularity because it is considered as an environmentally friendly manufacturing. Homemade FSW tool to be attached to a conventional milling machine was designed and fabricated. Experimental investigation of FSW process of the Aluminum alloy work piece to observe its heat generation was performed. Since heat generation is the main objective in a FSW process, the importance of identification of heat generation performance in a welded specimen is paramount. Heat generation of a welded specimen during FSW was measured using infra red thermal camera. The limitation of the measurement is it only captured the heat generation at surrounding area and surface of the welded specimen. Therefore, the heat generation inside contact area could not be identified. To overcome this problem, a finite-element model of the FSW process was developed. A model consists of a solid model of half the welded specimen since the symmetrical behavior of the geometry and boundary condition was assumed. Heat transfer analysis of a solid body model of a work piece was computed. It was observed that FSW parameters which involved dominantly in the heat generation were spindle speed, feeding rate and normal force. The heat generation model of FSW process was validated with the one from the experimental investigation. Good agreement between the numerical and the experimental investigation result has been made.


Author(s):  
M Song ◽  
R Kovacevic

A mathematical model to describe the detailed three-dimensional transient heat transfer process in friction stir welding (FSW) is presented. This work is both theoretical and experimental. An explicit central differential scheme is used in solving the control equations, the heat transfer phenomena during the tool penetrating, the welding and the tool-removing periods that are studied dynamically. The heat input from the tool shoulder is modelled as a frictional heat and the heat from the tool pin is modelled as a uniform volumetric heat generated by the plastic deformation near the pin. The temperature variation during the welding is also measured to validate the calculated results. The calculated results are in good agreement with the experimental data.


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