scholarly journals A Modified Analytical Heat Source Model for Numerical Simulation of Temperature Field in Friction Stir Welding

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Xiangqian Liu ◽  
Yan Yu ◽  
Shengli Yang ◽  
Huijie Liu

In the conventional analytical model used for heat generation in friction stir welding (FSW), the heat generated at the pin/workpiece interface is assumed to distribute uniformly in the pin volume, and the heat flux is applied as volume heat. Besides, the tilt angle of the tool is assumed to be zero for simplicity. These assumptions bring about simulating deviation to some extent. To better understand the physical nature of heat generation, a modified analytical model, in which the nonuniform volumetric heat flux and the tilt angle of the tool were considered, was developed. Two analytical models are then implemented in the FEM software to analyze the temperature fields in the plunge and traverse stage during FSW of AA6005A-T6 aluminum hollow extrusions. The temperature distributions including the maximum temperature and heating rate between the two models are different. The thermal cycles in different zones further revealed that the peak temperature and temperature gradient are very different in the high-temperature region. Comparison shows that the modified analytical model is accurate enough for predicting the thermal cycles and peak temperatures, and the corresponding simulating precision is higher than that of the conventional analytical model.

2007 ◽  
Vol 561-565 ◽  
pp. 279-282 ◽  
Author(s):  
Masafumi Kokubo ◽  
Shinichi Kazui ◽  
Takao Kaneuchi ◽  
Yoshimasa Takayama ◽  
Hajime Kato ◽  
...  

Microstructural characterization and temperature analysis have been performed in friction stir welding (FSW) of A383 and 5052 dissimilar aluminum alloys. Marked difference in microstructure was observed between joints with different arrangements of materials. The temperature at four points on each side of the joint line was measured during FSW in various conditions. In addition, an analytical model assumed that the work generated by the rotation of the tool led to the work for stirring materials and heat generation of the material and the tool. The temperature of the retreating side (RS) for the joint of the advancing side (AS):A383/RS:5052 was about 50K higher than that of AS, while the temperatures of AS and RS for the joint of AS:5052/RS:A383 were almost the same. The experimental temperature could be calculated reasonably by using the model with assumption of the work for stirring the material.


Author(s):  
Shubham Verma ◽  
Joy Prakash Misra

This research investigates the effect of process parameters on real-time temperature and forces distribution during friction stir welding of AA7039. Experiments are conducted at different rotational speed, welding speed, and tilt angle conditions. For the experimentation, a low-cost real-time force-measuring fixture is indigenously developed in-house. However, eight K-type L-shaped thermocouples are used to examine the real-time temperature distribution. The forces in the z-direction are of a higher magnitude than the x-direction. The maximum force in the z-direction of 3.25 kN is witnessed for 2° tilt angle and a minimum of 2.1 kN for 26 mm/min of welding speed. The maximum force in the x-direction of 0.97 kN is obtained at 2° tilt angle and a minimum of 0.27 kN is obtained at 1.3° tilt angle. The maximum temperature of 390 °C is observed at 1812 r/min, whereas a minimum of 283 °C is observed at 43 mm/min of welding speed. The variations in temperature and force distribution during friction stir welding are also evaluated by utilizing two phenomenological models.


2012 ◽  
Vol 16 (2) ◽  
pp. 527-534 ◽  
Author(s):  
Darko Veljic ◽  
Milenko Perovic ◽  
Aleksandar Sedmak ◽  
Marko Rakin ◽  
Miroslav Trifunovic ◽  
...  

A coupled thermo-mechanical model was developed to study the temperature fields, the plunge force and the plastic deformations of Al alloy 2024-T351 under different rotating speed: 350, 400 and 450 rpm, during the friction stir welding (FSW) process. Three-dimensional FE model has been developed in ABAQUS/Explicit using the arbitrary Lagrangian-Eulerian formulation, the Johnson-Cook material law and the Coulomb?s Law of friction. Numerical results indicate that the maximum temperature in the FSW process is lower than the melting point of the welding material. The temperature filed is approximately symmetrical along the welding line. A lower plastic strain region can be found near the welding tool in the trailing side on the bottom surface. With increasing rotation speed, the low plastic strain region is reduced. When the rotational speed is increased, the plunge force can be reduced. Regions with high equivalent plastic strains are observed which correspond to the nugget and the flow arm.


2018 ◽  
Vol 20 (1) ◽  
pp. 1-5
Author(s):  
Mohamed Habba ◽  
Mohamed Ahmed ◽  
Mohamed Seleman ◽  
Ahmed EL-Nikhaily

2016 ◽  
Vol 852 ◽  
pp. 260-266
Author(s):  
M. Selvaraj ◽  
G. Selvakumar

The heat generation during friction stir welding process influences the material flow, microstructure, and mechanical properties of the friction stir welded plates. This paper proposes a model for predicting heat generation and heat flux during the friction stir welding of AA 6061 aluminium alloy. The heat generation as a function of temperature, heat flux at the shoulder as a function of temperature, radius of shoulder and rotational speed and heat flux at the pin as function of temperature, radius of shoulder and rotational speed have been discussed. It shows that heat generation is inversely proportional to temperature, the heat flux at the shoulder and pin are directly proportional to radius of shoulder and rotational speed and inversely proportional to temperature.


2016 ◽  
Vol 5 (3) ◽  
pp. 234-240 ◽  
Author(s):  
Ahmed Ramadan Shaaban Essa ◽  
Mohamed Mohamed Zaky Ahmed ◽  
Abdel-Karim Yousif Ahmed Mohamed ◽  
Ahmed Essa El-Nikhaily

2021 ◽  
Vol 52 (3) ◽  
pp. 308-319
Author(s):  
T. Srinivasa Rao ◽  
M. Selvaraj ◽  
S.R. Koteswara Rao ◽  
T. Ramakrishna

Author(s):  
Shubham Verma ◽  
Joy Prakash Misra ◽  
Meenu Gupta

The present study deals with the application of sequential procedure (i.e. steepest ascent) to obtain the optimum values of process parameters for conducting friction stir welding (FSW) experiments. A vertical milling machine is modified by fabricating fixture and tool ( H13 material) for performing FSW operation to join AA7039 plates. The steepest ascent technique is employed to design the experiments at different rotational speed, welding speed, and tilt angle. The ultimate tensile strength is considered as a performance characteristic for deciding the optimal levels. The mechanical and metallurgical characteristics of the joints are studied by executing tensile and microhardness tests. It is concluded from the graphical analysis of the steepest ascent technique that the optimal maximum and minimum values are 1812–1325 r/min for rotational speed, 43–26 mm/min for welding speed, and 2°–1.3° for tilt angle, respectively. Besides, optical microscope and scanning electron microscope are utilized for microstructural and fractographic analyses for a better understanding of the process.


Author(s):  
Sanjeev Verma ◽  
Vinod Kumar

Aluminium and its alloys are lightweight, corrosion-resistant, affordable and high-strength material and find wide applications in shipbuilding, automotive, constructions, aerospace and other industrial sectors. In applications like aerospace, marine and automotive industries, there is a need to join components made of different aluminium alloys, viz. AA6061 and AA5083. In this study friction stir welding (FSW) is used to join dissimilar plates made of AA6061-T6 and AA5083-O. The effect of varying tool pin profile, tool rotation speed, tool feed rate and tilt angle of the tool has been investigated on the tensile strength and percentage elongation of the welded joints. Box-Behkan design, with four input parameters and three levels of each parameter has been employed to decide the set of experimental runs. The regression models have been developed to investigate the influence of welding variables on the tensile strength and elongation of the welded joint. It is revealed that with the increase in welding parameters like tool rpm, tool feed rate and tilt angle of the tool, both the mechanical properties increase, reach a maximum level, followed by a decrease with further increase in the value of parameters. Amongst different types of tool pin profiles used, the FSW tool having straight cylindrical (SC) pin profile is found to yield the maximum strength and elongation of the welded joint for different combinations of welding parameters. Multiple response optimization indicates that the maximum UTS (135.83 MPa) and TE (4.35%) are obtained for the welded joint fabricated using FSW tool having SC pin profile, tilted at 1.11° and operating at tool speed and feed rate of 1568 rpm and 39.53 mm/min., respectively.


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